A printable basepad and follower kit raises Magpul PMAG 17 GL9 magazines from 17 rounds to 23 plus one for USPSA Carry Optics competition while staying inside the division size rules. The original factory spring is kept and a single screw holds the extension in place.

The kit works only with Magpul PMAG 17 GL9 magazines and will not fit OEM Glock, ETS, or other aftermarket magazines. It is offered for competitive sports and education; users must follow magazine-capacity laws and should confirm magazines in a gauge before major matches.