The 13202X is a neon voltage stabiliser. The striking voltage is 75 Volts and the maintaining voltage is nominally 65 Volts. This example has a maintaining voltage of 58 Volts.
The etched lettering is faint but just visible. The electrodes are touching coils of wire.
The inner coil and the gap that determines the voltage. In use the envelope is filled with the orange neon glow.
Screw top caps were a feature in the early 1930s but this design dates from 1942.
The thin glass tube envelope is 23 mm in diameter, and excluding the Ct5 base pins is 100 mm tall.
Reference: Data-sheet. Type 13202X was first introduced in 1942. See also1942 adverts.
