F. of B.tablet
The Festival of Britain was held in 1951 for two main reasons.
1. To regenerate British business after World War two
2. To Celebrate the 100th anniversary of the Great Exhibition 1851
Once again many thousands of souvenirs were produced, but instead of an image of any of the iconic buildings most of the souvenirs were produced showing the even more iconic 'Symbol for the Festival' produced by Abram Games.
This is a small black plastic (or acrylic) tablet with a probably brass symbol inserted. Probably not a souvenir as such but a test piece for some other purpose