The RSA QD provides a forward attachment for the Magpul MS4 Sling and other push-button QD slings. Made from corrosion resistant steel, mounts on 1913 Picatinny rail, and places the attachment at an angle optimized for comfortable two-point sling use while maintaining easy push-button access.Push-button quick-detach sling swivel for 1-1/4" webbing, compatible with QD sling attachment points. Manganese-phosphate finished steel.