Shield Arms PMAG Gen 3 +5 Magazine Extension, Aluminum, Anodized, Finish, Black SA-ME-PMAG5-BLK The Shield Arms PMAG +5 Extension adds 5 rounds to your Magpul PMAG 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.