The ETA 842 is a mechanical watch movement introduced in 1949. It is an open face calibre with a bimetallic screw balance and features a Breguet hairspring. This movement, initially named Omega 38.5L T1, was later renamed to ETA 842. It offers stem winding and setting capabilities, as well as a sub-second function. The ETA 842 has been in use since 1949.