The CV1100 is vari-μ HF pentode. The prototype was the M-OV Type KTW62.
This tubular glass version was probably a later product made for replacement purposes. It has three wire grids.
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.
The internal coating hides the inner details.
Looking up from the base: a fuzzy image of the suppressor grid can be seen.
The top screen with the grid supports and the copper control grid support connects to the top cap.
The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 101 mm tall.