Shield Arms Glock 9mm Luger/.40 S&W 5 Round Magazine Extension Glock 19/23 5 Round Black 1 Pack Aluminum 5RD. Shield Arm's 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. Specifications for Shield Arms Glock 9mm Luger/.40 S&W 5 Round Magazine Extension: Manufacturer: Shield Arms Color: Black Finish: Anodized Magazine Capacity: 5 Round Caliber: 9mm Luger Gun Make: Glock Last Chance: Yes Package Contents: Shield Arms Glock 9mm Luger/.40 S&W 5 Round Magazine Extension What firearm models does the manufacturer say Shield Arms Glock 9mm Luger/.40 S&W 5 Round Magazine Extension is compatible with? The manufacturer suggests that Shield Arms Glock 9mm Luger/.40 S&W 5 Round Magazine Extension is compatible with Glock 17 Glock 22 Glock 19 Gen 3 Glock 23 Gen 3 Glock 19 Gen 4 Glock 23 Gen 4 Glock 23 Gen 5 Glock 19 Gen 5Shield Arms G19-ME-5-BLK-5RD: Glock 9mm Luger/.40 S&W 5 Round Magazine Extension Glock 19/23 5 Round Black 1 Pack Aluminum