The Revolution features many 5.56 parts; such as charging handle, bolt carrier, cam pin, buffer, heat sink barrel nut, handguard. The barrel extension, bolt assembly, upper and lower receiver are the exact same size as those on an AR15. The Revolution model is built on the Gen 4 lower receiver with ambidextrous controls and has a 14.5″ M-LOK MRR free-float handguard and POF’s standard 4.5 lb. drop-in trigger.