These quality replacement Glock pattern magazines are constructed with a hardened steel insert encased in high tech polymer. The polymer coating protects the magazine and prevents deformation, even when dropped. Specifications Weight: 0.3lbs Compatibility: Glock 17 / 17L / 18 / 19 / 19x / 26 / 34 / 45 Caliber: 9x19mm Capacity: 33 Rounds Body Material: Hardened Steel / Polymer Spring Material: Stainless Steel