The CV6035 is a packaged X-Band pulse magnetron operating at 9.555 to 9.645 GHz.
The output waveguide has to be pressurised in use.
The KB/Z identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the Z identifies the maker as MO Valve Company, Hammersmith.
This looks like a waveguide flange but is the input port for the forced air cooling. The shape of the magnet is clearly seen.
The thin metal tube envelope is 14 mm in diameter and is 138 mm tall.
