Safariland 7742152 7742-215-2 Joins Two Magazines Black Nylon

Safariland's Doubler affords quick, efficient reload with second magazine. Its design features a Top Round Protector to prevent the top round from being dislodged forward in the extra magazine due to firing of the weapon. It also ensures proper staggering by utilizing fixed standoff points molded into the carrier to prevent the magazines from moving relative to each other. The Doubler is constructed of a sturdy molded nylon case with three bolt.
This model is compatible with your AR15-style rifle with a 30 round magazine.