Magazine For Sig Sauer SIG522 .22 Long Rifle 10 RoundStyled after the SIG556 but chambered in .22LR. Sixteen inch barrel. Includes a metal receiver, collapsible folding and locking stock, Picatinny rail. Reliable blowback operation. Integrated M1913 Picatinny receiver rail for mounting optics. 7075-T6 Aircraft grade aluminum upper receiver with hard coat anodize finish. Lightweight polymer lower.