The Fontainemelon 701-2 is a mechanical watch movement featuring a pin lever escapement. It is equipped with a ratchet on the dial side and a crown mechanism with a rocker bar. The 051/04E is part of a series that includes the 051/01, 051/03, 051/03a, 051/04, and 051/04a, with only minor differences between them. This movement offers manual winding and includes a sub-second function. It was commonly used around 1955.