Spike's Tactical R2 30cal Muzzle Brake 5/8-24
 
This brake has extremely large side ports for diverting the gas followed by the projectile outwards for excellent recoil management. 
 
Specs
5/8x24
Material: 416 Stainless Steel
Thread: 5/8 X 24
Finish: Black Nitride
Features: Large Side Porting
Weight: 3.2oz