SIG Sauer M17 P320 ASP, CO2 Pellet Pistol, Coyote-Tan Replica of the U.S. Army M17 Pistol 20rd .177 Caliber Pellet Magazine Blowback Metal Slide RMP Belt/C02 Housing Drop Magazine Polymer Frame with Metal Slide Fixed White-Dot Sights Coyote Tan Color Field-Strippable 6lb Trigger Pull Weaver/Picatinny Accessory Rail Tech Tip: Not compatible with P320 20 round magazines (SIG-AMPC-177-20). The P320 magazine is too long to fit into the M17 housing.