The GD150M/S is a cold cathode voltage stabiliser. The mean voltage stabilised is 150 Volts. Between the 5 mA minimum current and 30 mA maximum current the voltage regulation is 6 Volts. The striking voltage is 185 Volts.
The direct equivalence between the GD150M/S and the 0A2 and CV1832 is given by all three designations being present on the glass.
The base connections and lower mica. The cathode cylinder has three supports/connections and the central anode connects to pin 5. There is sufficient left of the lettering to determine all the details.
The thin glass tube envelope is 18 mm in diameter, and excluding the B7G base pins, is 57 mm tall.