You can find the Aero Precision VG6 Gamma 5.56 Black Nitride here.

The Aero Precision VG6 Gamma is a high-performance muzzle brake and compensator hybrid that eliminates most recoil and minimizes muzzle movement. The combination of both braking and compensating allows the shooter to make rapid follow-up shots. The unique chamber geometries offer a very soft feel in the shoulder, and the gas ports dimensions have been strenuously tested to give the utmost control to the muzzle. The Gamma 5.56 is optimized to efficiently utilize gas from the muzzle on 10.5-18.5" barrel lengths, making it a perfect addition to almost any build.

Designed using state-of-the-art engineering techniques to eliminate felt recoil utilizing CFD (Computational Fluid Dynamics) and CAE (Computer Aided Engineering), the VG6 Gamma is 100% CNC machined from 17-4ph Heat Treated Stainless Steel for optimal performance. Includes a crush washer. Made in the USA.

Caliber: .223/5.56
Thread: 1/2-28 RH
Finish: Black Nitride