The CV75 (Commercially the 4313C) is a cold cathode thyratron based on the 4313C STC (UK) or 313C ITT (USA) design.
The KB/F identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the F identifies the maker as STC, Paignton.
The reverse carries the STC logo and the commercial Type of 4313C.
The anode is the rod within the glass tube. The split ring makes up the cathode and trigger electrode.
The gap between the cathode and trigger.
The wide glass tube envelope is 29 mm in diameter, and excluding the UX4 base pins is 69 mm tall.