There should be a model number somewhere on it that’ll tell you maximum wattage. It’s tough to say but I’d bet that’s a base for Mogul light bulbs (E39). It’s a good idea to know the maximum wattage of the fixture though.
Hmm interesting it’s kinda like a flood light but I suppose you could use it with a light bulb style grow light to direct it for more efficiency
Looks like the base reflector of a industrial type light.