You can find the Dead Air Armament Keymount Muzzle Brake 5.56 1/2x28 here. Fast $9.95 shipping! Orders over $200 ship for free!

The Dead Air Armament Keymount Muzzle Brake features the KeyMount quick attach system for your Sandman-L, Sandman-S, Sandman-K, or KeyMo equipped Nomad-30 suppressor. When shooting unsuppressed you can still employ the finest brake on the market and experience a flatter shooting rifle with minimal concussion compared to traditional muzzle brakes.

Caliber: .223/5.56
Length: 2.6"
Threads: 1/2x28