The CV9 is a high voltage power pentode with an 18 Watt anode dissipation. The CV9 specification was based on the commercial AL60.
The anode is supported on ceramic insulators. The control grid is fitted with radiating fins on top of the copper support rods.
The oval cathode with the white oxide coating has three wire grids passing over it. The cooling fins for the control grid are clearly seen. The top mica is an interference fit to the envelope but sits above the anode support mica.
The classic envelope is 43 mm in diameter, and excluding the B7 base pins is 128 mm tall.