The Chuch'e-Po is an improvement over the Tŏkch'ŏn artillery piece, which was mounted on an ATS-59 chassis. There are at least four M1991 versions of the Chuch'e-Po, each mounting a different gun; the D-30 122mm, D-74 122 mm, the M-46 130 mm and the ML-20 152 mm howitzer. A fifth M1992 version is armed with the SM-4-1 130mm howitzer. These artillery pieces can be identified by their six road wheels, as compared to the Tok-Ch'on's five, and a prominent recoil cylinder which protrudes from the turret. Another major difference is the fact that the Chuch'e-Po has a fully encased rounded turret, as opposed to the older open-topped self-propelled artillery pieces used previously.