The CV8458 (commercially the EL95) is an output pentode with low heater consumption designed initially for car radios. It would also provide adequate audio power for a domestic receiver or smaller stereo system. The EL95 was also used in push-pull to produce six to seven Watts of output.
The maker's name is not present but the print is in a font used by Mullard.
The stitched anode.
The heat radiating fin is on the screen grid.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 52 mm tall.