Bosch 3 position SH/UH 1/1 fire truck switch

Bosch 3 position Switch SH/UH 1/1 fire truck switch Old Bosch 3 position switch SH UH 1/1 in used condition. The rear diameter is about 4,5 cm and the front diameter is about 3 cm. The knob is 4 cm length. The switch has 3 positions (0-1-2). The rear is stamped with "BOSCH, GERMANY, SH/UH 1/1, 56". Made in Germany. The switch was mounted in a fire truck.