The Mec-Gar® Glock® 17 9mm 18-Round Anti-Friction Magazine is an aftermarket magazine designed for proper fit and function with the Glock 17. Built from durable carbon steel with an anti-friction coating, this magazine is designed for superior strength and lasting corrosion resistance in almost any self-defense or range day environment. The high-tensile music wire spring and high-impact green follower ensure smooth, consistent feeding in high-stress target and defensive situations, while a high-impact polymer floor plate offers added drop resistance that's ideal for quick mag swaps. Plus, this magazine increases your carry capacity while maintaining a flush-fit profile. Works with factory magazine release buttons. Does NOT require a metal button upgrade.