Multi-function AR-15 basepad incorporates many features: Rocker base provides support, even when shooting up/down hill +3 Capacity adds Extra Firepower Non-Skid base grips earth/grass/slippery surfaces Accepts detachable coupler (sold separately) Machined from billet 6061 aluminum Fits the 20-, 30-, and 40-round "Gen3" MagPul PMag Outside review by famed 3-gunner Patrick Kelley = https://www.facebook.com/patrick.e.kelley/videos/1646167985405823/ Due to US State Department restrictions, we cannot ship this part internationally. CA residents should consult their latest regulations prior to ordering.