AIM Sports Inc AR-15 .223/5.56 Crush Washer 12 Pack Black Small. 223 / 5.56 caliber crush washer insures proper indexing of muzzle brakes and flash hiders. (12 Pieces Per Pack) Specifications for AIM Sports Inc AR-15 .223/5.56 Crush Washer: Manufacturer: AIM Sports Inc Additional Features: Pack of 12 Gun Model: AR-15 Features of AIM Sports Inc AR-15 .223/5.56 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 AR-15 .223/5.56 Crush Washer What firearm models does the manufacturer say AIM Sports Inc AR-15 .223/5.56 Crush Washer is compatible with? The manufacturer suggests that AIM Sports Inc AR-15 .223/5.56 Crush Washer is compatible with AR-15AIM Sports Inc ACWA1: AR-15 .223/5.56 Crush Washer 12 Pack Black Small