The MSA (MOE Sling Attachment) attaches directly to MOE Hand Guards and Forends, providing a forward sling attachment point for the Magpul MS3(R) Sling and other clip-in sling systems. Like the RSA(R), the MSA is constructed of durable, case-hardened steel and it's finished with Melonite(TM) for extreme resistance to wear and corrosion.