Spikes Tactical SAKB0100 Barking Spider2 Muzzle Brake Black Nitride 4140 Chromoly Steel with 1/2"-28 tpi Threads, 3.75" OAL & 1.40" Diameter for 5.56x45mm NATOThe Barking Spider is designed to redirect the noise, blast, and concussion forward away from the shooter (down range). It was specifically designed to handle full auto and high volume fire. The Barking Spider features a cutting edge blast cone design which is supported in both the front AND the rear. This feature not found on any other Krinkov muzzle brake eliminates the cone from sagging in extremely high temperatures. It is CNC machined from Billet