Introduced in 1937, the Type 97 was basically a copy of the ZB 26/30 pattern light machine gun adapted to use in Japanese tanks and armored cars. The adaptations included mounting an optical sight to the left side fo the action, moving the iron sights to the right, and moving the recoil spring to wrap around the gas piston so that a folding stock could be used. About 15,000-17,000 of these guns were made in 7.7x58mm (rimless), and used to equip all of the tanks and armored cars in Japanese service from 1937 until the end of World War Two.