A 2.4 cm curvy square, the orange/grey colours covered with a clear acrylic. The chrome 'frame' inside has a rough finish, intended to help it catch the light. In the silver is the golden text : Apex - 1890 - 1990 - Centenary. It has a good pin and safety catch. Thanks for looking and any questions, please ask. Thanks also for appreciating that I am no expert & have done my best with description / research in my determination to help this find a new collection/owner. (PS: 5p only for scale and not included)