The Alpina 651 watch movement features a pin-lever escapement and a ratchet on the dial side, along with a crown mechanism with a rocker bar. Its unique design enables direct sub- or sweep second functions using the same plate and bridges by exchanging the positions of the 2nd and 4th wheels. For the sweep second variant, an intermediate wheel is added to couple the center pinion with the minute wheel at the sub-second position. This movement also benefits from having only one wheel overlapping the barrel in the center, allowing for a moderate height in a pin-lever movement. Additionally, the Alpina 651 movement offers manual wind, sweep second, and calendar functions with a date set by +/-24h. This movement was commonly used around 1960.