The Eterna 852U watch movement is an open face calibre movement with a stem mechanism that allows for both winding and setting. It features an imitation of balance screws which contribute to its precision. Additionally, the movement utilizes a pillar design with the cannon pinion and minute wheel placed between the plates, resulting in a low profile. The escapement can be easily observed through large inspection holes, facilitating servicing. This movement also incorporates a sub-second function. The Eterna 852U movement was manufactured around the 1950s.