The Omega 28.10RA watch movement, developed in 1965, is the first movement with a frequency of 36000 A/h. It features an automatic mechanism with two roller freewheels and a ball-bearing rotor. The movement incorporates a worm screw regulation gear and is based on the manual wind calibre AS 1687/1688. The 31.7 movement, a collaborative development of Doxa, Eberhard, Favre-Leuba, Girard-Perregaux, and Zodiac, shares similarities with the 31A movement, and the exact differences between the two are not known. The functions of the Omega 28.10RA movement include automatic winding, sweep seconds, and a ball-bearing rotor. The movement was primarily used around 1965.