MERCURY has been meticulously engineered to provide superior recoil reduction and neutralize muzzle rise with a smooth, balanced release of blast energy. Progressive 90 side ports vent combusting gases at intervals that spread out the recoil impulse for efficient, accurate follow-up shots. MERCURY is the choice for those seeking a compact, lightweight muzzle device with smooth recoil characteristics and Dynamount on-barrel sight compatibility. A timing nut is included for easy installation. RSR -