Promag SIGA20 OEM 9mm Luger Sig Sauer P320 21Rd Blued Steel Detachable This Replacement Or Spare Magazine Is Compatible With Your Sig Sauer P320. It Is constructed Of Heat Treated Steel With Injection Molded Mag Follower And Mag Spring Formed From Chrome Silicone Wire. Made In The USA. Caliber: 9mm Luger Capacity: 21Rd Model: OEM Material: Steel Model Fit: P320 Brand Fit: Sig Sauer Capacity: 21 Manufacturer: Promag Mfg Number: SIGA20 Model: OEM