AIM Sports Inc AR10/308 Crush Washer 12 Pack Black Small. 308 caliber crush washer insures proper indexing of muzzle brakes and flash hiders. (12 Pieces Per Pack) Specifications for AIM Sports Inc AR10/308 Crush Washer: Manufacturer: AIM Sports Inc Additional Features: Pack of 12 Gun Model: AR-10 Features of AIM Sports Inc AR10/308 Crush Washer No gunsmithing required Thread flash hider / muzzle brake and torque 15-20lbs. Ensures proper indexing of flash hider / muzzle brake Package Contents: AIM Sports Inc AR10/308 Crush Washer What firearm models does the manufacturer say AIM Sports Inc AR10/308 Crush Washer is compatible with? The manufacturer suggests that AIM Sports Inc AR10/308 Crush Washer is compatible with AR-10AIM Sports Inc ACWA2: AR10/308 Crush Washer 12 Pack Black Small