The CV4097 is a special quality RF beam tetrode for battery equipment and operating at up to 100 MHz.
The filament has two sections an in series consume 230 mA at 5 Volts. The anode dissipation is five Watts. and typically the valve will generate 2.4 Watts of RF output.
The KB/E identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the E identifies the maker as Thorn-AEI, Brimsdown.
The anode is blackened and the beam plate are bright. Inside the grids and filaments can be seen.
Looking along the grids through a gap in the side of the anode.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 58 mm tall.
Reference: Data-sheet. Type CV4097 was first introduced in 1955. See also1955 adverts.