Advanced polymer construction Transparent carbon smoke design Steel wire spring Injection-molded polymer follower and floor plate UV/temperature-resistant design Lifetime warranty The ETSA(R) 9mm 10-Round Carbon Smoke Magazine for GlockA(R) 17 Pistols is a performance-enhanced aftermarket Glock-pattern magazine, designed to deliver factory-like reliability and consistent performance without breaking the bank. The impact-resistant polymer tube offers lasting strength and reliability, and the transparent design allows for superior clarity and quick visual round counts while on the move. Further, this magazine comes equipped with a high-strength steel wire spring and anti-tilt polymer follower for dependable operation, while the creep-resistant feed lips ensure superior stability. If that's not enough, ETS uses a proprietary polymer that's extremely chemical, heat, and UV resistant for lasting service you can truly depend on when it matters most. Made in USA.