ETS mags won't crack or break, are resistant to heat, cold, UV and harsh chemicals and won't become brittle over time. Their mags come with enhanced features like non-tilt followers, creep-resistant feed lips and clear body allowing you to see count and ammo type, leaving nothing to chance. Fits the Glock 17, 18, 19, 19x, 26, 34, and 45 New and improved internal geometry increased feeding reliability across all ammo types including steel and aluminum casings