Two-piece machined steel muzzle brake employs an adjustable, push-down, spring-tensioned, rotating cover design with three port hole sizes to choose from to direct combustion gases upward to virtually eliminate muzzle rise and felt recoil. Enables fast, accurate follow-up shots in semi-auto mode and superb control in full auto. Designed by Greg Carlson especially for reloading enthusiasts who enjoy experimenting with different powder weights, bullet grains, and loads for increased velocities and shooting performance. Cover is selectable for either a large, medium or small gas vent port by depressing the knurled selector cylinder and aligning port and cover hole; release cover to activate locking pin mechanism. Gas escapes upward to counteract upward force on the muzzle without directing concussion and noise back at the shooter. Solid bottom prevents kicking up dust signature when shooting prone.