The EPSILON 556SL BBSS is the ideal muzzle brake for 14.5" rifle builds. Featuring an outside diameter of .745", the EPSILON 556SL can be pinned and welded to your barrel while still allowing full maintenance and removal of your gas block without having to remove the muzzle device. The EPSILON 556SL utilizes a new aggressive chamber design that improves gas flow and reduces felt recoil significantly. It also features deep channel cuts that greatly reduce the overall weight toward the front end of your build. Slim in design does not mean slim in performance. Users can still expect the same great performance they have grown to trust from VG6 Precision muzzle brakes. NOTE: The CAGE Device is NOT compatible with the Epsilon 556SL.