The MPX Copperhead features a monolithic Elite Series upper receiver, with an integrated stock knuckle lower, and a 4.5" barrel with integrated muzzle brake. Unconventional design, unmatched performance, and familiar AR handling. The SIG MPX redefines the submachine gun category with a new level of operator safety, in-field adaptability and proven reliability in the harshest environments. Completely ambidextrous, the SIG MPX is great for left- or right-handed shooters with its dual-sided selector switch, magazine release, charging handle and bolt release.