This is a factory replacement 20-round magazine for the MCX-SPEAR. SIG SAUER designed this magazine for the U.S. Army’s Next Generation Squad Weapon System (NGSW) XM7 Rifle. It has been engineered to withstand the extreme demands of the U.S. Army and is specifically designed to deliver increased performance when using a suppressor. The MCX-SPEAR offers next-generation performance along with the capability of the U.S. Army’s XM7 rifle in a civilian version.