MAG SHIELD FITS GLOCK 17 +5/4 EXT BK

17 round 9mm magazine for Glock 17 OEM 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.