L or R - Horizontal Mounted Double M4 Left or Right. This Mag Pouch pocket is designed to carry (4) 30 round magazines stacked 2 per pocket. This Mag Pouch closes with Velcro flap and side release buckle. There is also a pocket behind the mag. Pouches that can be used as a utility pocket or will accept the holster portion of our envelope holster. This Mag Pouch attaches to belt or vest with strap attaching system. *envelope holster not included