All Glock mags  encase a toughened and hardened steel insert in Polymer 2. As a result this steel insert protects the magazine lips.  Invented by Gaston Glock himself, Polymer 2 is a high strength nylon-based polymer. Therefore, this polymer makes the Glock Magazine incredibly durable.

• 1 Composite fabrication of toughened steel and Glock Polymer 2.
• 2 Viewing ports for visual confirmation of loaded rounds
• 3 High capacity twin-stack design
• 4 Heat treated steel magazine spring
• 5 Shock absorbing Glock Polymer 2 base plate