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, 140mm Competition Mag 22-Round Carbon Smoke Magazine for GlockA(R) Pistols is a performance-enhanced aftermarket pistol magazine, specifically engineered for volume shooters. Built around an impact-resistant polymer tube this magazine offers lasting strength and reliability, while 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 resistant to chemicals, heat, and UV rays for lasting service and unparalleled reliability in virtually any environment. Made in USA.