This rare fusebox holds a single fuse. It's the correct part for many British cars of the 1940s and 1950s, including Land-Rover Series I, Alvis, Riley, Rover and others.
This is a new old stock part, brand new and never fitted to a car. It could be used as an auxiliary fuse for fog or spotlamps, a radio, or just to cover a circuit that the factory didn't bother to protect with a fuse at all (lots of British cars, such as Jaguar Mark I and 2 and MGAs, had no fuse at all for the headlamps, taillamps, coil, fuel pump, etc. !).