-
How to Pick Your Next AR 15 Charging Handle | from BRD(Post)
AR 15 Charging HandlesAt first glance, an AR 15 charging handle looks like nothing more than a regular, rod-shaped object that doesn’t have much significance. Truth be told, the charging handle ...
Best AR15 Charging Handle for 2024(Post)&nb ...
​The Ultimate Guide to Customizing Your AR-15: Top Parts and Upgrades(Post)The Ultimate Guide to Customizing Your AR-15: Top Parts and UpgradesThe AR-15 platform is renowned for its versatility, reliability, and customization potential, making it a favorite among firearm en ...
AR 15 Parts Guide For 2023 | AR 15 Parts List(Post)AR 15 Parts Guide For 2023Welcome to the AR-15 Parts Guide for 2023, where we dive into the exciting world of AR-15 customization and explore the top components to enhance your rifle's performan ...
Upgrade Your Arsenal: Best AR-15 Parts to Buy from 2024(Post)As AR-15 enthusiasts, we all know that the right parts can make or break your rifle's performance. Whether you're looking to improve accuracy, durability, or overall versatility, 2024 has brought ...
Top 10 must have AR-15 Accessories from 2025(Post)The AR-15 rifle, celebrated for its adaptability, precision, and modular design, remains one of the most versatile firearm platforms in 2025. Its broad appeal spans tactical shooters, competitive s ...
The Complete Guide to AR-15 Lower Parts Kits: What You Need to Know (Post)When building or upgrading an AR-15, selecting the right lower Parts Kit is crucial to functionality and reliability. These kits include the essential components needed to complete your lower r ...
The Timber Creek Outdoors Lineup of AR15 Parts(Post)Who is Timber Creek Outdoors?Timber Creek Outdoors (TCO) is a family-owned company of outdoorsmen who are committed to producing the finest quality products for shooting enthusiasts. For over 50 ye ...
Complete Vs. Custom AR-15 Lower Parts Kits: Which one Fits Your Build?(Post)AR-15 Lower Parts Kits: Complete Guide for Builders and Enthusiasts When building or upgrading your AR-15, choosing the right AR-15 lower parts kit (LPK) is critical to ensure optima ...
How to Choose a Quality AR-15 Lower Parts Kit: Essential Tips for Builders(Post)Choosing a high-quality AR-15 lower parts kit (LPK) is critical for anyone building or upgrading their rifle. With many options available, it’s essential to understand what to look for and ...
Must Have AR 15 Accessories | Best AR 15 Accessories(Post)While every AR 15 owner is different and therefore has different needs and wants, these are a few of the must have AR 15 Accessories every shooter needs. Well, need is a stretch, but you get th ...
The Top 5 AR-15 Lower Parts Kits For Every Budget In 2025(Post)Building or upgrading an AR-15 rifle is a journey that requires careful consideration of each component, and one of the most critical pieces of the puzzle is the AR-15 lower parts kit. This ...
Top AR-15 Accessories to Optimize Your Bushmaster Rifle(Post)Bushmaster is a name that resonates strongly within the AR-15 community. It is known for producing reliable, high-performance rifles that suit various needs. Established with a focus on innovation ...
How to Assemble an AR 15: A Step-by-Step Guide(Post)Introduction to AR-15 Assembly The AR-15 is one of the most popular and versatile firearms today, known for its modularity, accuracy, and reliability. Whether you're a firearm enthusiast, a ...
A Beginner's Guide to Choosing AR-15 Accessories(Post)A Beginner's Guide to Choosing AR-15 Accessories The AR-15 rifle is known for its highly modular design, making it one of the most customizable firearms on the market. With countless AR-15 accessor ...
Best barrel length for AR-15(Post)Best barrel length for AR-15Selecting the ideal barrel length for your AR-15 can significantly improve your shooting experience, whether engaging in long-range precision or maneuvering through mid-ra ...
Top 7 AR-15 Complete Uppers in 2025: Top Picks for Performance and Reliability(Post)When building a new rifle, your complete upper is critical in determining its performance and reliability. Whether you're a seasoned enthusiast or just starting your AR-15 journey, selecting a high-q ...
Essential Guide to AR-15 Lower Parts Kits: What Every Builder Should Know(Post)Selecting the right AR-15 lower parts kit is one of the most critical steps in building or upgrading your rifle. Whether assembling your first AR-15 or customizing your existing setup, choos ...
The FAB Defense GLR-16 AR 15 Lower Build Kit(Post)BRD’s FAB Defense GLR-16 AR 15 Lower Build KitThe FAB Defense GLR-16 AR 15 Lower Build Kit is a superb upgrade for your rifle. It provides you with enhanced versatility with its stock extension and ...
AR-15 or AK-47: The Ultimate Rifle Showdown(Post)AR 15 vs. AK 47Drawing from Black Rifle Depot's extensive experience in the firearms industry, I've had the unique opportunity to shoot both the AR-15 and AK-47 in various modes, including semi and f ...
Top AR-15 Accessories for Your Ruger AR-15 Rifle: Enhance Performance and Precision (Post)Ruger rifles are celebrated for their impeccable craftsmanship, reliability, and modularity, making them a favorite among AR-15 enthusiasts. Whether you're a seasoned shooter or just starting your ...
AR 15 Parts Explained: The Beginners Walk Thru(Post)The AR-15: America’s Rifle The AR-15 is widely considered America's Rifle. The AR platform is an easy-to-assemble and use shooting system. It is an excellent tool for sports and defense alike.
Build Your Dream Rifle on a Budget | AR 15 Rifle Build(Post)Build Your Dream Rifle on a Budget Building a custom AR 15 is a dream for many gun enthusiasts. However, the cost of parts can quickly add up, putting a custom build-out of reach for many shoote ...
What You Need to Know About AR 15 Handguards | from BRD(Post)AR 15 HandguardsJust like every other part of the firearm, AR 15 handguards come in plenty of different options and are very modular. With all of these options available, it can sometimes be con ...
DIY Guide: How to Build an AR-15 or Choose the Right AR-15 Build Kit(Post)When optimizing your AR-15, choosing the right accessories can make all the difference. From improving performance to enhancing versatility and aesthetics, AR-15 accessories allow you to tailor ...
The Colored AR 15 Parts at Black Rifle Depot(Post)Colored AR 15 Parts are TrendingThe popularity of colored AR15 Parts is exploding in 2022. In fact, an inventory specialist at Black Rifle Depot told me. “The number of colored parts we are now selli ...
How to Field Strip an AR 15 | AR 15 Disassembly(Post)Let’s first hope you are bored at work thinking about going out this weekend to shoot your new AR 15 and are wondering how to field strip your rifle after shooting to clean it before packing it bac ...
The Quick Guide to AR 15 Parts and Accessories(Post)A Brief History of the AR 15 The AR-15 semi-automatic rifle has an unmemorable history. It was designed in 1956 by Armalite. In 1959, the patent to the AR-15 was sold to Colt. It was marketed ...
Best AR-15 Parts for 2025(Post)The AR-15 remains one of the most popular firearms in the United States, celebrated for its modularity, versatility, and widespread parts availability. Whether used for sport shooting, home defense ...
Choosing the Right AR-15 Upper Length for Defense or Hunting(Post)Choosing the right AR-15 upper length is critical when building or upgrading your rifle. Whether you prioritize quick maneuverability for home defense or long-range accuracy for hunting, barr ...
Design and Build Your Custom AR 15 on a Budget(Post)The Easiest Way to Build Your Own AR 15 Rifle or PistolIf you go to any off-the-shelf gun centers and buy an entry-level mil-spec AR15, you will likely end up with an A2 System. They often come sta ...
What to Consider When Choosing an AR15 Lower Build Kit(Post)Comparing AR 15 Lower Build Kits: Unraveling the DifferencesIn assembling AR-15s, it's critical to understand that not all lower-build kits are identical. Gaining insight into these kits' essent ...
How to Attach A Sling To Your AR 15 | Black Rifle Depot(Post)Choosing the proper sling depends on the purpose, the rifle, and the shooter. There is no one-size-fits all when it comes to slings. There are however, a few things to consider to make the choice eas ...
Top AR-15 Rifle Kits from 2024: Build Your Ultimate Rifle(Post)Building your AR-15 rifle can be one of the most rewarding experiences for gun enthusiasts. In 2024, an impressive lineup of rifle kits has emerged based on Black Rifle Depot’s top-selling product ...
Must Have AR-15 Accessories for Hunting Builds(Post)The AR-15 is an incredibly versatile firearm, capable of adapting to various applications, including hunting. While traditionally viewed as a tactical rifle, the AR-15 has evolved into a highly cu ...
Best AR-15 Handguards - MOE SL Handguard(Post)In the world of AR-15 customization, handguards not only protect the barrel but are pivotal in enhancing the rifle's overall functionality and aesthetics. Among the myriad options available, the Magp ...
The Best AR 15 Magazines | A Close Look at AR15 Mags(Post)What are AR 15 Magazines?A magazine is a storage device for bullets, either internally fixed (within the gun) or externally attached (on the outside of the gun). It helps hold a defined number of b ...
AR-15 Charging Handles(Page) AR-10/.308 Charging Handles(Page) Frequently Asked Questions About AR-15 Parts(Page)Frequently Asked Questions about AR-15 Parts At the heart of every AR-15 enthusiast's journey is a quest for knowledge. Below, we've answered the most commonly asked questions about AR-15 parts to h ...
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
-
Radian Raptor-SD Ambidextrous Charging Handle
Radian Weapons
$129.95 - $139.95Radian Raptor-SD Ambidextrous Charging Handle Suppressor-Optimized, Ported Design for Superior Gas Redirection The Radian Raptor-SD Ambidextrous Charging Handle is engineered specifically for...$129.95 - $139.95 -
Presma AR-15 Ambidextrous Charging Handle
Presma
MSRP: $26.95 - $28.95$19.95 - $21.95Presma Inc Ambidextrous AR-15 Charging Handle Brand new product that allows both right and left-handed shooters to easily charge their AR-15. Also useful for 3 gun shooting and for training off-hand...MSRP: $26.95 - $28.95$19.95 - $21.95 -
Breek Arms Sledgehammer AR-15 Ambidextrous Charging Handle
Breek Arms
MSRP: $79.99$69.99Breek Arms Sledgehammer AR-15 Ambidextrous Charging Handle Upgrade your AR-15 with the Breek Arms Sledgehammer Charging handle. The Sledgehammer features an ambidextrous design that caters to both...MSRP: $79.99$69.99 -
Out of stock
POF Tomahawk Ambidextrous AR 15 Charging Handle
Patriot Ordnance Factory
MSRP: $104.00$99.95POF Tomahawk Ambidextrous AR 15 Charging Handle While the shape and laser engraving is inspired by the design of the POF-USA American Patriot Tomahawk, the Tomahawk AR 15 Charging Handle has...MSRP: $104.00$99.95 -
Out of stock
POF Strike Eagle Ambidextrous AR 15 Charging Handle
Patriot Ordnance Factory
MSRP: $104.00$85.99POF Strike Eagle Ambidextrous AR 15 Charging Handle The Strike Eagle ambidextrous AR 15 Charging Handle with slightly oversized serrated wings ensures a positive engagement whether you...MSRP: $104.00$85.99 -
Aero Precision BREACH AR 15 Ambidextrous Charging Handle
Aero Precision
MSRP: $94.00$76.95Aero Precision BREACH AR 15 Ambidextrous Charging Handle The Aero Precision BREACH is a rugged, ambidextrous, precision-manufactured charging handle for the AR15 platform. The BREACH's design...MSRP: $94.00$76.95 -
Out of stock
Radian Raptor SD Ambidextrous Charging Handle - AR 10/SR 25
Radian Weapons
$159.95Radian Raptor SD Ambidextrous Charging Handle - AR 10/SR 25 The silencer-optimized Raptor-SD features a ported shaft designed to redirect gasses down and forward, away from the shooter's face when...$159.95 -
AERO Precision AR 10 Breach Ambidextrous Charging Handle w/ Large Lever - Black
Aero Precision
MSRP: $119.00$94.95AERO Precision AR 10 Breach Ambidextrous Charging Handle w/ Large Lever - Black The AERO Precision AR 10 Breach Ambidextrous Charging Handle with Large Lever in Black is built for the M5/AR308...MSRP: $119.00$94.95 -
AERO Precision AR 10 Breach Ambidextrous Charging Handle w/ Small Lever - Black
Aero Precision
MSRP: $119.00$94.95AERO Precision AR 10 Breach Ambidextrous Charging Handle w/ Small Lever - Black Engineered for the M5/AR308 platform, the BREACH is a tough and reliable charging handle built to withstand the most...MSRP: $119.00$94.95 -
Radian Raptor Ambidextrous Charging Handle
Radian Weapons
$104.95 - $139.95Radian Raptor Ambidextrous Charging Handle The Radian Raptor Ambidextrous Charging Handle is one of the most popular premium Ambidextrous Charging Handles on the market. Made by Radian...$104.95 - $139.95 -
Out of stock
AERO Precision AR 15 Ambidextrous Charging Handle
Aero Precision
MSRP: $105.00$99.95AERO Precision AR 15 Ambidextrous Charging Handle The Aero Precision AR15 Ambidextrous Charging Handle features a profound design with left and right side activation levers to charge your...MSRP: $105.00$99.95 -
Out of stock
Radian Raptor-SL Ambidextrous Charging Handle
Radian Weapons
$94.95 - $104.95Radian Raptor-SL Ambidextrous Charging Handle Based on the proven Raptor™ Ambidextrous Charging Handle, the Raptor-SL™ features slim-line handles for customers who require an ultra...$94.95 - $104.95 -
Strike Industries Ambidextrous Magazine Release - Version 2
Strike Industries
MSRP: $41.95 - $43.95$34.95 - $36.95Strike Industries Ambidextrous Magazine Release Strike Industries Ambidextrous Magazine Release was designed to slip into lowers designed to accept a mil-spec magazine catch. They have a low...MSRP: $41.95 - $43.95$34.95 - $36.95 -
Radian Raptor-LT Ambidextrous Charging Handle
Radian Weapons
$79.95 - $84.95Radian Raptor-LT Ambidextrous Charging Handle The newest member of the Radian family, the Radian Raptor-LT Charging Handle features all of the great functionality of the original Raptor Charging...$79.95 - $84.95 -
Breek Arms Warhammer Micro AR-15 Charging Handle
Breek Arms
MSRP: $49.99$44.99Breek Arms Warhammer Micro AR-15 Charging Handle Upgrade your AR-15 charging handle for improved performance with the Warhammer Mod2 Micro Latch Ambidextrous Charging Handle from Breek Arms. The...MSRP: $49.99$44.99 -
Wilson Combat AR-10 Bullet-Proof Ambidextrous Charging Handle
Wilson Combat
MSRP: $92.95$89.95Wilson Combat AR-10 Bullet-Proof Ambidextrous Charging Handle Durable, Ergonomic, and Ambidextrous Control The Wilson Combat AR-10 Bullet-Proof Ambidextrous Charging Handle sets a new standard in AR...MSRP: $92.95$89.95 -
Out of stock
CMMG Ambidextrous Safety Selector
CMMG
$29.95CMMG Ambidextrous Safety Selector The CMMG Ambidextrous Safety Selector is designed to cater to both left and right-handed shooters, ensuring versatile and ergonomic firearm handling. Meeting or...$29.95 -
Out of stock
POF Ambidextrous Selector Switch
Patriot Ordnance Factory
MSRP: $34.00$32.95POF Ambidextrous Selector Switch The POF-USA ambidextrous safety selector is a drop in upgrade designed to increase the shooters' options and maximize the efficiency of taking the rifle from "fire"...MSRP: $34.00$32.95 -
Griffin Armament SNACH Gen 2 Ambidextrous AR-15 Charging Handle
Griffin Armament
MSRP: $84.95$81.00Griffin Armament SNACH Gen 2 Ambidextrous AR-15 Charging Handle The Griffin Armament SN-ACH (Suppressor Normalized Ambidextrous Charging Handle) features a gas vent that directs excess gas away from...MSRP: $84.95$81.00 -
Out of stock
Razor Ambidextrous Safety Selector
Black Rifle Depot
$14.95Razor Ambidextrous Safety Selector The AR 15 Ambidextrous Safety Selector allows for the shooter to engage the safety from both sides of the AR 15 Lower Receiver. With added texture to the thumb...$14.95 -
ODIN Works Ambidextrous Modular Safety
Odin Works
MSRP: $54.00 - $55.00$51.30 - $52.25ODIN Works Ambidextrous Modular Safety Everyone who runs and AR15 platform knows that the correct possitioning of your controls makes a big difference in how effectively you can control the...MSRP: $54.00 - $55.00$51.30 - $52.25 -
Out of stock
LBE Unlimited Ambidextrous End Plate
LBE Unlimited
MSRP: $12.99$11.95LBE Unlimited Ambidextrous End Plate Introducing the LBE Unlimited Ambidextrous End Plate – a versatile and durable addition to your AR-15 platform. Crafted from robust steel and finished in...MSRP: $12.99$11.95 -
Rise Armament AR-10 Ambi Charging Handle - Black
Rise Armament
MSRP: $99.99$89.99Rise Armament AR-10 Ambi Charging Handle - Black The Rise Armament Ambidextrous Charging Handle Assembly is the ideal charging handle for both left- and right-handed shooters. Precision machined...MSRP: $99.99$89.99 -
Out of stock
Enhanced Ambidextrous Safety Selector
Trinity Force
MSRP: $17.95$14.95Enhanced Safety Selector The Trinity Force AR Ambidextrous safety selector can be installed on any standard AR lower receiver and will function when deployed on either the right or left side of the...MSRP: $17.95$14.95 -
Out of stock
Bravo BCMGUNFIGHTER Mod 3x3 Ambi Charging Handle - 5.56/.223
Bravo Company USA Inc.
MSRP: $96.00$92.95Bravo Company BCMGUNFIGHTER Mod 3x3 Ambidextrous Charging Handle (5.56/.223) Introducing the Bravo Company BCMGUNFIGHTER Mod 3x3 Ambidextrous Charging Handle (5.56/.223) - the pinnacle of innovation...MSRP: $96.00$92.95 -
Aero BREACH Ambi AR15 Charging Handle - Small Lever
Aero Precision
MSRP: $94.00$76.95AERO Precision BREACH Ambidextrous AR15 Charging Handle - Small Lever The AERO Precision BREACH Ambidextrous AR15 Charging Handle with Small Lever is a rugged, precision-manufactured charging...MSRP: $94.00$76.95 -
Out of stock
Timber Creek Ambidextrous Safety Selector (Red)
Timber Creek Outdoors
$39.95Timber Creek Outdoors Ambidextrous Safety Selector (Red) The Timber Creek Outdoors Ambidextrous Safety Selector is a great way to upgrade your weapon. Mil-Spec components are tough, and...$39.95 -
Ambidextrous Safety Selector
Black Rifle Depot
MSRP: $18.95$15.95Ambidextrous Safety Selector Enhanced Ergonomics for Both Right- and Left-Handed Shooters The Ambidextrous AR-15 Safety Selector is designed to improve the usability of your AR platform by...MSRP: $18.95$15.95 -
Out of stock
Radian Raptor Competition Ambidextrous Charging Handle
Radian Weapons
$104.95 - $114.95Radian Raptor Competition Ambidextrous Charging Handle Precision, Speed, and Ambidextrous Functionality for AR-15 Rifles The Radian Raptor Competition Ambidextrous Charging Handle offers a...$104.95 - $114.95 -
Out of stock
Timber Creek Outdoors Ambidextrous Safety Selector (FDE)
Timber Creek Outdoors
$39.95Timber Creek Outdoors Ambidextrous Safety Selector (FDE) The Timber Creek Outdoors Ambidextrous Safety Selector is a great way to upgrade your weapon. Mil-Spec components are tough, and...$39.95 -
Out of stock
Aero Precision BREACH Ambi AR-15 Charging Handle - OD Green
Aero Precision
MSRP: $94.00$76.95AERO Precision BREACH Ambidextrous AR-15 Charging Handle - OD Green The Aero Precision BREACH Ambidextrous AR-15 Charging Handle in Black/Tan is a high-quality charging handle designed for...MSRP: $94.00$76.95 -
Out of stock
Timber Creek Outdoors Ambidextrous Safety Selector (Black)
Timber Creek Outdoors
$39.95Timber Creek Outdoors Ambidextrous Safety Selector (Black) The Timber Creek Outdoors Ambidextrous Safety Selector is a great way to upgrade your weapon. Mil-Spec components are tough, and...$39.95 -
Out of stock
Aero Precision BREACH Ambi AR-15 Charging Handle - Black/Tan
Aero Precision
MSRP: $94.00$76.95Aero Precision BREACH Ambidextrous AR-15 Charging Handle - Black/Tan The Aero Precision BREACH Ambidextrous AR-15 Charging Handle in Black/Tan is a high-quality charging handle designed for the AR15...MSRP: $94.00$76.95 -
RISE Armament AR-15 Ambi Charging Handle and Safety Selector Combo
Rise Armament
MSRP: $159.98$109.99RISE Armament AR-15 Ambi Charging Handle and Safety Selector Combo You'll experience faster and smoother charging on your AR-15 with the RISE Ambidextrous Charging Handle. The ambidextrous latches...MSRP: $159.98$109.99 -
Out of stock
Aero BREACH Ambi Charging Handle -Tan/Black - Small Lever
Aero Precision
MSRP: $94.00$76.95AERO Precision BREACH Ambidextrous AR15 Charging Handle -Tan/Black - Small Lever The AERO Precision BREACH Ambidextrous AR15 Charging Handle with Small Lever is a rugged,...MSRP: $94.00$76.95 -
Out of stock
UTG Pro Ambidextrous Pistol Grip - Black
Leapers / UTG
MSRP: $16.97$14.97UTG Pro Ambidextrous Pistol Grip - Black This is the UTG Pro ambidextrous pistol grip for the AR 15. The ergonomic symmetrical palm swells reduce fatigue and improve handling comfort. Its nonslip...MSRP: $16.97$14.97 -
Radian Raptor SD-SL Ambidextrous Charging Handle
Radian Weapons
$124.95 - $134.00Radian Raptor SD-SL Ambidextrous Charging Handle Slim Profile and Suppressor-Optimized Design for AR-15 Platform The Radian Raptor SD-SL Ambidextrous Charging Handle combines low-profile...$124.95 - $134.00 -
Out of stock
Aero BREACH Ambi Charging Handle - OD Green - Small Lever
Aero Precision
MSRP: $94.00$76.95Precision BREACH Ambidextrous AR15 Charging Handle - OD Green - Small Lever The AERO Precision BREACH Ambidextrous AR15 Charging Handle with Small Lever is a rugged,...MSRP: $94.00$76.95 -
Aero Precision M5 BREACH Ambidextrous Charging Handle
Aero Precision
$97.95 - $99.00Aero Precision M5 BREACH Ambidextrous Charging Handle The Aero Precision BREACH is a rugged, ambidextrous, precision-manufactured charging handle for the M5/AR308 platform. The BREACH's design...$97.95 - $99.00 -
Out of stock
Timber Creek Ambidextrous Safety Selector (Robin's Egg Blue)
Timber Creek Outdoors
$39.95Timber Creek Outdoors Ambidextrous Safety Selector (Robin's Egg Blue) The Timber Creek Ambidextrous Safety Selector is a great way to upgrade your weapon. Mil-Spec components are tough,...$39.95
Featured
Rise Armament RA-140 Drop-in Trigger
Rise Armament
Mil Spec AR 15 Stock and Buffer Kit
Black Rifle Depot
AR 15 Lower Build Kit
Black Rifle Depot
AO Precision C158 SP/HPT/MPI 5.56 Black Nitride Bolt Carrier Group
AO Precision
Upper Parts Kit for Glock 19
Black Rifle Depot
Upper Parts Kit for Glock 17
Black Rifle Depot
Lower Parts Kit for Glock 17
Black Rifle Depot
AR 15 Forward Assist
Black Rifle Depot
Lower Parts Kit for Glock 19
Black Rifle Depot
Armaspec SFT45/90 Ambi Safety Selector
Armaspec
Strike Industries Billet Magazine Catch
Strike Industries
Rise Armament RAVE-140 Super Sporting Flat Drop In Trigger
Rise Armament
Surplus Complete Lower Parts Kit
Black Rifle Depot
Anderson Manufacturing Stripped AR 15 Upper Receiver
Anderson Manufacturing
Stainless Steel Gas Tubes
Black Rifle Depot
AR 15 Charging Handle
Black Rifle Depot
Strike Industries AR 15 Ultimate Dust Cover
Strike Industries
AR 15 Carbine Buffer Tube Kit
Black Rifle Depot
Strike Industries Forward Assist Kit (Black, Blue, FDE, Red)
Strike Industries
.750 Low Profile Gas Block - Black Nitride
Black Rifle Depot