Hmmm.
I'm going to guess that you are the proud owner of a Velocette motorcycle. The image you've furnished is a tool for it.
The only question is what beast do you have?MSS, VIPER, VENOM, SCRAMBLER, ENDURANCE, CLUBMAN, THRUXTON.
Velocette's were made by Veloce Ltd, in Hall Green, Birmingham. England, 1904 - 1971.
AA