Shield Arms Blem Z9 Magazine Extension Glock 43 9 mm Luger 9 Round + 3 Round Powercron Black. The Z9 is a steel magazine and is the same length as the OEM Glock magazine with pinky extension but holds an additional 3 rounds. Glock pistols and magazines are known for reliability - the Z9 maintains that same Glock reliability while giving you a 50 percent increase in magazine capacity in the same overall footprint. We recommend swapping out your plastic OEM mag catch with either our standard steel mag catch or our premium steel mag catch. Here's why. If you don't swap your mag catch you may have reliability issues. If you use another manufacturer's mag catch you may have reliability issues. Powercron is a cationic epoxy coating that offers excellent corrosion resistance and low VOC in a lead-free film electrocoat surface finish. If you are in a humid or salt water environment or if you sweat a lot we recommend Powercron Electroless Nickel or Black Electroless Nickel finish. Note: because we have multiple Powercron vendors there may be slight cosmetic variations in the finish. This is cosmetic only and does not affect performance. If you are concerned about a matching finish from mag to mag you might be happier with one of the electroless nickel finishes. Features of Shield Arms Blem Z9 Glock 43 9 mm Luger 9 Round + 3 Round Magazine Extension 9 round capacity; Same length as an OEM Glock 43 magazine with pinky extension; Powercron finish; Easy to remove impact resistant base pad; Three base pad color options: Black Grey or Red; Package Contents: Shield Arms Blem Z9 Glock 43 9 mm Luger 9 Round + 3 Round Magazine Extension Shield Arms Z9PM9PC: Blem Z9 Magazine Extension Glock 43 9 mm Luger 9 Round + 3 Round Powercron Black