The E2004 is an M-OV development sample of what became the U41 EHT rectifier.
The value of 15 kV appears written on the label with the letters P-L. The rated PIV of the production valve is 33 kV and 15 kV would be the maximum sine wave input.
The envelope below the anode is shielded by an internal white coating.
Top view: the anode is fixed only to the top cap. The three supports are held in a glass bead at the top and are spot welded to the anode bell.
The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 86 mm tall.
References: Data-sheet & M-OV A and E Types. Type CV2115 was first introduced in 1953. See also1953 adverts.
