The CV493 is the commercial 6X4 HT rectifier. A common cathode is employed passing through two anodes arranged at right angles to one another.
At 325-0-325 input to the rectifier this will give an HT rail higher than is required for most domestic equipment. Use for audio amplifiers and small transmitters is most probable, or driven at 250 volts for radio receivers.
The two anodes are identical in shape, one with side fins up and the other with them pointed down.
The mica discs are of single thickness and thus not protected against vibration.
The thin glass tube envelope is 18 mm in diameter and the length, excluding the B7G base pins, is 57 mm.