This AR-15 pistol length black nitride gas tube with roll pin is 6 3/4″ inches long and made from high quality heat treated stainless steel Mil-Spec dimensions. The extremely durable black nitride finish on the pistol length gas tube for corrosion resistance, wear resistance and look great under your AR hand guard and it match the rest of the black AR-15 parts. Fits most pistol length gas systems.