Cobel said:
Can anyone tell me about this gauge. What are the numbers on the inner dials.
That's a Smiths 'Revolator' commonly fitted to Triumphs and Royal Enfields during the fifties/early sixties.
The inner dials show revs in each gear (working outwards from 2nd, 3rd, 4th) however, for the rev scales to be accurate the Revolator needs to match a specific model of motorcycle. If you can give the number at the bottom of the dial, then it may be possible to identify which particular make/model it belonged to.