Hera USA Linear Compensator, 223 Rem/556NATO, Black Finish, 1/2X28 Threads. 11-04-09 .223 / 5.56 (max. 7.62mm) Linear Compensator for use on short barreled rifles. The inside design with 12 separate expansion chambers leads blast and noise straight forward to increase shooting comfort and reduce noise at the shooters ears. Generation 2 with 30% less weight and a reduced outside diameter for perfect fit under Hera IRS handguard systems.