Shield Arms S15 Magazine Features The Shield Arms S15 magazine is machined from steel with raised ribs on the back that match the OEM magazine position in the mag well eliminating tolerance stacking issues that can occur across different Glock frame variations. The Gen 3 construction uses a new slightly thicker steel with a new heat treat process and a standard black nitrocarburized QPQ finish giving the magazine a high degree of corrosion resistance for long-term reliability. The pre-installed +2 extension is machined from billet 6061 aluminum and Type 2 anodized adding 2 rounds of capacity while keeping the magazine easy to remove from most aftermarket flared mag wells. Index cuts on the extension body improve grip when drawing the magazine from a pouch under pressure. A unique easy access floor plate design lets the spring and follower be serviced or cleaned without removing the extension from the magazine body simplifying maintenance compared to typical extended magazines. Each magazine includes an 11-coil power spring for reliable feeding across the extended capacity. Shield Arms notes that swapping the factory plastic mag catch for one of their steel mag catch offerings is required for full reliability since these magazines are designed around that steel catch geometry. Backed by a 100% lifetime warranty and the Spring for Life guarantee this magazine gives Glock 43X/48 owners a durable made-in-USA way to add real capacity to a compact carry pistol. Shield Arms S15 Specifications Brand: Shield Arms Model: S15 Gen 3 Compatible Hosts: Glock 43X Glock 48 Caliber: 9mm Capacity: 17 Material: Steel Finish: Black Nitrocarburized QPQ Weight: 0.16 lbs Available At: GrabAGun