Ultimate Arms Gear .223 5.56 AR15 AR-15 M4 M16 Secure Steel & Zinc Bodied Universal Firearm Gun Handgun Pistol Revolver Shotgun Rifle Protective Key Trigger Block Lock The Ultimate Arms Gear secure trigger lock is designed to fit most AR rifles. For superior durability and security it is constructed of hardened steel and zinc while it is fitted with innovative rubber pads to shield the firearm from scratching or marring whatsoever. The lock is designed to easily and safely lock in and unlock out of place in a matter of a few seconds and includes 2 sets of standard keys. When it comes to preventing unauthorized use of your firearm, Ultimate Arms Gear is the choice for an affordable, simple, and safe solution. Includes a lifetime warranty against any manufacturing defect in original materials and workmanship.