could anyone shed any light on the date these lights were introduced, i imagine in there day they were used as lightweight replacement for dynamos?

Cheers Mick

Sorry, I have no idea, but tell us more about it please.

Any brand name? Is this battery powered? If so what battery spec? The bad view of the mount tab suggests an older design (stamped steel) and the shape of the tab suggest a fit to a preexisting something. Did this come on a bike to you? If so a photo of the light mounted as it was would provide more context. Andy.

And welcome to BF!

We like a mystery. But we like to solve them better. Does this have wire terminals or inner batteries?

It's marked Drydex by exide and it is powered by a D size battery, it was passed on to me by a friend

from Google, looks similar

https://www.worthpoint.com/worthoped...ycle-472646452

"Back in the day".....most of the battery powered lights were for occasional, short time period use when used alone. The French bikes also often fitted them along with generator lights so that they could be turned on for use as standlights when riding in start and stop conditions-such as in a town- so that they would remain lit. It's a cool light.....

Thanks for that, it must have been the latest lightweight technology i guess in the 1930s or 40s.

Is your light that old?

What is the shell made out of?
What is the lens made out of?

Sure, its made from brass and the lense is plastic.