XM26 is a modular Accessory Shotgun System (MASS). Which can be used as an under-barrel shotgun attachment. Invented by C-More system and manufactured by Vertu Corporation, It was first named as Lightweight Shotgun System (LSS). And now it is officially named as XM26 Modular Accessory Shotgun System (MASS). XM26 is using detachable magazines which hold five 12 gauge rounds. It is a modular, manually operated, pump action shotgun.