Shield Arms +1 mag extension for your Z9 magazine. Our unique easy access floor plate dsign allows you to quickly access the spring and follower without having to remove the extension from the magazine body. Comes with a 100% lifetime warranty and the Shield Arms Spring for Life guarantee. - Magazine Extension Features - Unique easy access floor plate design to service or clean the magazine body without the need to remove the magazine extension from the magazine body. - Index cuts on the extension body to increase grip when coming out of a magazine pouch. - Machined from billet 6061 aluminum - Type 2 anodized - 12 coil plus power spring included - Adds 1 round to the Z9 magazine - Fits Shield Arms Z9 magazine only - Proudly made in the USA - Lifetime warranty