The IWC 402 watch movement is an open face calibre with an indirect minute and hand friction clutch on the barrel. It features a stem mechanism located between its plates. If equipped with three jewels, it consists of a balance with two bearing jewels and one cap jewel, along with a lever that has steel pallets. Its functions include stem winding and pin setting, as well as a sub-second display. The J38 movement was utilized during the period of 1928 and onwards.