Combining impact-resistant polymer construction with tough steel inserts, numbered witness holes, and steel internal springs, the Glock® 17, 19, 26, 34 Gen4/5 9mm 33-Round Factory Magazine is a genuine factory OEM magazine, engineered to deliver incredible firepower and unwavering reliability with a variety of double-stack-compatible Glock pistols. Glock 9mm magazines are duty-tested and combat-ready, making them the most trusted brand among law enforcement and military professionals across the globe.