PROCOMP-556-1/2-28 The advanced SureFire ProComp 556 muzzle brake, which fits M4/M16 weapons and variants with 1/2-28 muzzle threads, greatly reduces both recoil impulse and muzzle rise so that the weapon tracks straight back to keep you on target for faster shot-to-shot recovery. Its patented Impulse Diffusion design minimizes side blast and rear-directed concussion effects. The ProComp 556 duplicates the design of the SureFire SOCOM SFMB-556-1/2-28 muzzle brake, but unlike the latter it cannot be used to mount SureFire SOCOM suppressors. Precision machined from US mill-certified steel bar stock including high-precision cut threads for optimum thread interface the ProComp 556 muzzle brake has a black Melonite finish that provides maximum protection under harsh environmental conditions. The SureFire ProComp 556 muzzle brake has a blind pilot hole at the 3 and 9 o'clock position to enable fine-tuning of recoil characteristics for individual shooting styles or ammunition characteristics. Each ProComp 556 muzzle brake is covered by SUREFIRE®s No-Hassle Promise. FITS: M4, M16 and variants with 1/2-28 muzzle threads NOTE: SureFire ProComp muzzle brakes are stand-alone muzzle devices and do not serve as mounts/adapters for any SureFire Fast-Attach sound suppressors. Features Offset porting greatly reduces recoil impulse and muzzle rise so the weapon tracks straight back to keep you on target for faster shot-to-shot recovery Precision machined from US mill-certified steel bar stock High-precision barrel threads for optimum thread interface Pilot holes for tuning of muzzle brake and to pin-and-weld on short-barreled rifles Black Melonite coating provides maximum protection against harsh environmental conditions Installation requires no permanent modifications for M4 / M16 / AR15-type weapons Restrictions ITAR Notice Export of the commodities described herein is strictly prohibited without a valid export license issued by the U.S. Department of State, Office of Defense Trade Controls, prescribed in the International Traffic in Arms Regulation (ITAR), Title 22, Code of Federal Regulations, Parts 120-130.