Replaces the magazine floor plate and factory magazine spring adding grip length. Installation of this component requires the removal of the detachable magazine well. This extension will not increase the capacity of the magazine. If you remove the factory plus base plate and install this product the 10mm magazine will become a 10 round magazine and the 45ACP will become 9 rounds. Fits XDME 10mm and 45ACP as well as all XD series compact/subcompact magazines in 10mm and 45.