Rail section is made of Hard Anodized Aircraft Aluminum Alloy; Mounting hardware is made of Corrosion Resistant Stainless Steel; Made to the Mil-Standard 1913 Picatinny Arsenal Specifications; Lengths: 3-inch (5 slot); Features a Snag resistant design, while retaining Mil-Standards specs; Self-contained assembly, eliminates the possible loss of mounting hardware; Fits ALL KeyMod interface mounting surfaces; Black Finish