This RIS Standard Milspec Barrel Nut \ Adapter works with any upper receiver that has MILSPEC barrel nut threads. It will simply screw onto the front of the gun allowing your handguard to be free floating. For use with these RIS Handguards
OD: 1.47" or 37.4mm, ID: 1.00" or 24mm, W: 1.89" or 48mm
OD: 1.47" or 37.4mm, ID: 1.00" or 24mm, W: 1.89" or 48mm
