HEXMAG Magazine, 223 Remington/556 NATO, 20 Rounds, Fits AR Pattern Rifles, Polymer, Black HX20-AR15-BLK The HEXMAG AR-15/M4/M16 Shorty 20 round magazine is ideal for any sport" competitor or tactical shooters demanding superior strength" proven reliability" and exceptional value. Features include; redesigned feed lip geometry to maximize strength and versatility" stripper clip guides for faster reloading" a deep catch pocket for rock-solid stability" one of the industry's only true tool-less designs for easy cleaning" heat-treated stainless steel spring for extended storage periods.