Our Black Nitride gas tubes are made out of Mil-Spec 304
stainless steel and then are Nitride treated for greater heat
resistance, corrosion resistance, and lower reflection. These gas tubes are great for all calibers, including .223, 5.56, 300 blackout, 5.45x39, 7.62x39 or any other AR15 variant. The low glare black gas tubes eliminate any glare underneath the hand guard. Black Nitride is also known as SBN, melonite, QPQ and so forth. Comes with Roll pin.