The RSA provides a low profile forward sling attachment point for the Magpul MS3® or MS4® and other clip-in systems. Made from QPQ salt bath nitrided steel for wear and corrosion resistance, the RSA attaches to any 1913 Picatinny rail. It has passed stress tests of over 300 pounds while weighing in at a mere 1.3 ounces. Made in the USA.