6V Bosch RKLE 90H beacon lamp

Bosch RKLE 90H lamp without lens in used condition. I put 6 Volt on the lamp and it rotates. It looks like that the bulb holder is missing. I put a bulb on the cable and after that the bulb did not burn and the lamp did not rotate (maybe a ground problem). The badge is stamped with "BOSCH RKLE 90H Blau, 7782300207, Glühlampe H1 6V 55W, Eisemann GmbH Stuttgart Germany, B1031, 71226, 21Bl" and the motor is stamped with "6V". Made in Germany.