Strike Industries Aluminum Extended Mag Plate for Glock G17/G22 boosts your Glock's performance by adding +5 9mm or +4 .40 cal rounds to OEM double stack magazines. Crafted from lightweight durable 6061-T6 aluminum this plate is designed with a slow drag no-snag profile for seamless reloads. Comes with an additional locking aluminum plate for enhanced security. Perfect for shooters seeking capacity and reliability in their Glock magazines.