3 Piece Rail Combo Pack – Sylvan Arms' Qd Rail Mount Combo is the best combination for attaching your firearm accessories and sling. They are designed for quick and easy removal and attachment. For on the fly changes at the field range or tactical applications. Includes Sylvan Arms' 7 and 3 slot Picatinny rail mounts and their Sling quick connect. Designed for M-Lok Rails. Made of black anodized 6061-T6 Aluminum.