Features Include: Machined from a solid block of 7075-T651 aluminum on our multi-axis CNC mills to exacting tolerances, with a tight fit to minimize slop that exceeds military specifications. The AES10 is sold as a match set for precision, long-range work. Specs 7.62mm / .308 Cal Set DPMS pattern set (DPMS rail high rail height) Integrated and enlarged trigger guard Flared magazine well Threaded upper tensioning screw hole (nylon tip set screw included) Type III, Class 2 hard