The NR43 (later renamed CV1167) is an output pentode based on the Mullard PM24A.
This exhibit was made in Canada by General Electric and the GE logo is on the base cap.
The bright anode of this low power pentode.
Here the twin loops of the oxide coated filament are seen held in the hooks of the tensioning springs. The slot in the top mica allows the wire grids to be seen.
A closer look.
The classic envelope is 44 mm in diameter and, excluding the B5 base pins, is 93 mm tall.