Compatible with M-LOK mounting systems commonly found on buttstocks like the MDT ESS and SRS V5 (and newer); Long 5" surface to better interact with a variety of bags to allow for more in-line recoil characteristics; Rounded front and side surfaces to reduce snagging and catching; Slim profile to match up with buttstock width; No rear overhang to interfere with LOP or buttpad adjustments; 6061-T6 aluminum construction; Mil-spec Type II hard anodized finish to stand up to repeated usage; Weight: 0.215lb (aluminum version)