The Elgin 381 is a open face calibre watch movement introduced in 1914. It features a bimetallic screw balance with a riveted staff and an optional monometallic screw balance with a press-fit staff. The movement utilizes a Breguet hairspring, while the lever and escape wheel are made of brass. The balance with a press-fit staff and with a riveted staff can be seamlessly interchanged with the hairspring. The J16 movement is capable of stem winding and setting, as well as exhibiting a sub-second function. Its period of use extends from 1914 onwards.