Shield Arms Extended Magazine, Glock 17 OEM, 9MM, 22 Rounds, Fits Glock 17, Aluminum Material, Anodized Finish, Black G17-ME-5INS-BLK Glock 17 OEM 17 round 9mm magazine with an anodized Shield Arms +5 magazine extension pre-installed. 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.