The striking Volts are 110 and for burning currents of 2 - 10 mA the regulation is 5 Volts.
Pin 4 is a priming anode. This allows discharge to ignite when a heavy shunt load is across the main terminals. The attached data-sheet has details of how to connect this pin.
We have another example of this valve. Note the dark interior to the glass.
Unusually for a CV valve this one has the GEC logo sticker attached. The sticker says made for GEC.
The thin glass tube envelope is 17 mm in diameter and, excluding the B7G base pins, is 45 mm tall.
Reference: Data-sheet. Type CV286 was first introduced in 1954. See also1954 adverts.
