The CV9994 (commercially the ZA9) is a beam tetrode with a 10 Watt anode dissipation and a 200 mA heater for series chain use. The 5B/104D is equivalent.
The KB/FE identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the FE identifies the maker as STC, Oldway (Additional to Paignton factory 'F').
This valve was made in England by STC but carries the parent company's identification of ITT.
Looking into the top a copper grid support and two heater folds are seen.
The wide glass tube envelope is 28 mm in diameter and, excluding the IO base pins, is 70 mm tall.