Designed between American Precision Arms and Adaptive Tuning Systems, the Fat Tuna attaches to the Gen 3 Fat Bastard Muzzle Brake helps reduce blast/concussion, tunes factory loads, and increases accuracy. This is especially useful for shooting specific factory ammo that doesn’t work particularly well in your rifle, when your barrel is speeding up post break-in, or when temperature swings are beginning to impact accuracy. The geometry on the front of the Fat Tuna is specifically designed to counteract the blast flow on the Fat Bastard port. The initial gas flow that has already generated the directional force to reduce recoil is redirected and creates a shield of gas that reduces sound waves and percussive energy. The result is a significant reduction on the concussion the shooter feels without sacrificing recoil reduction. Features: Attaches to the Gen 3 Fat Bastard Muzzle BrakeHelps reduce blast/concussion, tunes factory loads, and increases accuracyReduces concussion the shooter feels without sacrificing recoil reduction American Precision Arms APA Fat Tuna 3/4x24 Tuning System for Fat Bastard Brake FATUNA34