Aero Precision, Low Profile Adjustable Gas Block, Fits AR15 with 0.936" Barrel, Nitride Finish, Black NEW WARNING Warning WARNING WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov. Machined from 4140 steel Compatible with barrels utilizing a .936 gas block journal Nitride coated Attaches to barrel via 10-32 x 3/16 knurled set screws Product Description The Aero Precision Adjustable Gas Block allows the user to finely tune their gas system for any application. This is particularly useful for managing excess gas to reduce blowback on suppressed firearms, or competition builds where the shooter is looking to mitigate recoil.