Fits 9mm, 40cal, 45acp Double stack Magazines.
These have an added gap between the pouches to accommodate for magazine pouches with long baseplates such as M&P and CZ magazines. Also the Gen5 Glock magazines.
Note: This pouch will spill over into the adjoining Molle channels about .25" on each side. Normal Kywi pouches have an overlap of about 1/8".