Pocket Magazine Holder - for Steel Mags - NeoMagNeoMag is designed specifically for metal magazines. For Glock OEM Magazines use NeoMag Type G. Sizing is simple Regular ( For a standard magazine base ) Extended. ( For extended magazines or deeper concealment ) Works with all Single and Double stack magazines Sizing Exceptions: For Metal Mags Wilson Combat 9mm single stack choose Large Check Springfield XD magazine to make sure they are magnetic STI 9mm mags need a size large Type G NeoMag. Does not