SIERRA 5 XENO 5.56MM RIFLE SUPPRESSOR From the beginning, Dead Air's mission has been to give No Quarter in design, performance, and technology. The Sierra 5 stands true to that mission by giving you everything you want out of a dedicated 5.56 silencer. This is a hard-use silencer. Dead Air is not cutting costs or decreasing lifespan by using stainless steel baffles. They are not sacrificing durability in search of saving a few ounces. The Sierra 5 is full-auto rated with no barrel length restrictions. Love or hate the knurling, it's function over form, directly inline with their goal when developing the Sierra 5. Frankly, if you don't get the Sierra 5 red hot Mfg: Dead Air Armament