Hanhart is a German watch company which developed its first alarm movement 301 in 1952. It's a movement with a joint spring barrel for alarm and time. It also used bezel for handling the alarm hand. First versions didn't have a  on/off button, but the alarm could be stopped by turning the bezel (and alarm hand). In version 2, the On/Off pusher was added on the left side of the case. So 301 ver 2. was simmilar to Baumgartner BMG 90.

A very unusual additional plate at the back side of the watch was introduced together with this movement. It was used for additional rise of the case from the hand (to better hear the alarm) but it could also be used for additional support so that the watch could be used as a table watch.

Hanhart used this movement just for their own watches and for the export to the USA, where company Merit exclusively used their movements.

Later the improved 302 movement was introduced, where bezel function was replaced by additonal crown. That crown had also it's function in winding (it had to be pulled out in order to wind the movement with the another crown).

I have only watch with 301 ver.1 movement in my collection.