The Rearden Mfg SPB (Short Port Brake) is a compact, high-efficiency muzzle brake designed for shooters who demand both performance and suppressor compatibility. With a 1/2x28 thread pitch and durable black nitride finish, the SPB is built for precision rifle builds, AR platforms, and SBRs chambered in 5.56 or similar calibers. Its compact design reduces overall length while maintaining excellent recoil control and flat-shooting performance. Engineered with optimized port geometry, the Rearden SPB effectively mitigates recoil and muzzle rise without excessive blast or side concussion. The black nitride finish provides corrosion resistance and long-lasting durability in harsh environments. It's also compatible with Rearden's Atlas and other suppressor mounts using the R-Series taper interface, giving shooters a streamlined path to suppressed fire without changing muzzle devices. Whether for duty, competition, or range use, the SPB delivers control and flexibility in a compact footprint. Specifications: Thread Pitch: 1/2x28 TPI Caliber Compatibility: 5.56 NATO / .223 Rem Material: Heat-treated steel Finish: Black Nitride Length: Approx. 1.8" Design: Short Port Brake (SPB) - reduced length, balanced recoil control Made in USA