The SIG SAUER LE Adaptive Carbine Platform (ACP) allows any handgun with an accessory rail to be quickly modified into a personal defense weapon or carbine style firearm. Regardless of the brand, most pistols equipped with an accessory rail can be mounted to the ACP without the need for modification to the base gun. ACP will accept most railed guns with barrels up to 5" in length. Fabricated from solid aircraft-grade aluminum, the ACP sports M1913 rails at the 3, 6 and 9 o’clock positions with a full-length top rail at the 12 o’clock position. Compatible accessories such as lights, red dot sights and lasers can be mounted for additional functionality. NOTE: This National Firearms Act-regulated military/law enforcement model features a top folding shoulder stock. Civilian purchasers must comply with the requirements for registering a short-barreled rifle.