This exhibit is a battery Class B audio power amplifier based on the Cossor 220B and in this instance made by Cossor.
The pre-CV RAF designation is VR32. It became the CV1032. The UK Army designation was AR16.
The Air Ministry identification of a crown with the letters AM.
The dome carries the Cossor name and within can be seen the twin triodes. The close wound grid and filament tension spring of the left triode is in sharp focus. The top mica side fingers can be seen to tightly grip the glass walls.
The classic envelope is 44 mm in diameter and, excluding the B7 base pins, is 93 mm tall.