Kci Usa Inc KCI-MZ049 10/15Rd 40 S&W Black Hardened Steel/Polymer These KCI USA's Glock Pattern magazines Are constructed With a Hardened Steel Insert That Are encased In Polymer. The Polymer Molding helps To Protect The Magazine Body From Damage And deformation From Regular Use. Caliber: 40 S&W Capacity: 10/15Rd Material: Hardened Steel/Polymer Capacity: 10/15 Manufacturer: KCI USA Inc Mfg Number: KCI-MZ049