The CV248 photocell is designed to operate with 160 Volts on the anode and was based on the commercial GS16.
The KB/OS identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the OR identifies the maker as Rank Cintel, Sidcup.
The half cylinder photo-cathode with the wire ring anode in front.
Face view.
Looking at the top shows the anode support insulated by a glass bead.
The thin glass tube envelope is 25 mm in diameter, and excluding the B4 base pins is 56 mm tall.
