Switch lever rheostat made by the Gebr. Kaiser company, Leipzig.
For motor 220 volts, 1/5tel PS.
The two buttons on the right side allow to adjust two different motor speeds.
The lever is operated by a pneumatic motor. When activated from the music roll, it pulls the lever to the left and the motor will speed up.
This rheostat is from a red Welte push-up (Vorsetzer).