The Shield Arms Glock 19/23 Magazine Extension adds 5 rounds to your Glock 19 magazine and 4 rounds to your Glock 23 magazine. Our 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 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 - Adds 5 rounds to Glock 19 9mm - Adds 4 rounds to Glock 23 40 S&W - Comes with a +10% power spring - Fits OEM Glock 13 and 15 round magazines only - Proudly made in the USA - Fits most aftermarket flared mag wells - Lifetime warranty