These 50-round Glock pattern drum magazines are glass-filled polymer construction in all black. They feature heat-treated, high carbon steel, spiral torsion springs. The load assist lever provides quick and easy loading. Due to the weight of the loaded magazine, they are not designed to be DROP FREE. Disclaimer: Lifetime Warranty VOIDED if customer disassembles magazine! This magazine is not designed to be used with hollow point ammo. For use in Glock patterned pistols. Specifications Weight: 1.5lbs Compatibility: Glock 17 / 17L / 18 / 19 / 19X / 26 / 34 / 45 Caliber: 9x19mm Capacity: 50 Rounds Body Material: Composite/Glass-Filled Polymer Spring Material: High Carbon Steel