The Shield Arms S15 Magazine Extension adds 5 rounds to your S15 magazine. Their unique, easy access floor plate design 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.Features :Unique easy access floor plateIndex cuts on the extension bodyMachined from billet 6061 aluminumType 2 anodizedAdds 5 rounds to Shield Arms S15 Gen 2 magazine12 coil plus power springProudly made in the USAFits most aftermarket flared mag wellsLifetime warranty