Don't lose precious seconds in competition or combat fumbling for a spare magazine during a reload. This rugged speed loading system clamps directly to the lower receiver of any AR-15/M16 rifle or carbine and securely holds a second, fully loaded magazine alongside the mag well for super-fast mag changes. More reliable and easier to use than improvised methods, like taping two magazines together, that can cause malfunctions at critical moments. Closed-top design protects the spare mag from rain, dirt, dust, and debris and prevents the top round from jumping forward under recoil. Independent release system lets you drop the spare mag and the mag in the weapon separately to allow tact Mfg: Boonie Packer Products SPECS: Steel, Parkerized, or 6061 T6 aluminum, hardcoat anodized, both dark gray, with reinforced molded polymer BCE and spacer. 3A 1/2" (8.9cm) long, 2A 1/2" (6.4cm) wide, 2A 3/4" (7cm) high. Weight: 8.4 oz. (234g) (steel), 5.6 oz. (159 g) (aluminum). Fits AR-15/M16/M4 ri