Add two rounds of capacity to your SA AICS (metal), ARC, Accurate International, and MDT (metal) magazine with the MK Machining Pro Series Magpul AICS +2 extension. Redesigned shape for increased strength and durability. Now printed from tough PA12 Nylon Material. Easily installs in under a minute, simply remove baseplate and slide on extension. Proudly printed on top notch machines from PA12 Nylon. Extremely lightweight, lifetime warranty, and made in the USA! Reuses stock spring and follower.