The Strike Industries AR Modular Magazine Release (MMR) offers a quick and simple way to configure your mag button preference to one of three (3) included options. No need to remove the mag catch if you want to change the button. A simple push of the magazine button adapter using an object that fits in the space allows for a quick and simple swap of the magazine button. The SI MMR comes with included Standard Extended and Oversized buttons so you always have the modularity to swap at home or at the range. The mag buttons are textured for positive feel and manipulation of your AR for enhanced ergonomic control. The provided mag buttons are made from lightweight polymer paired with SUS630 stainless steel shaft sleeve and mag button adapter. Included as well is a steel magazine catch along with a magazine spring to give you everything out of the package for a drop-in installation.