I'm having a problem finding a supplier for lighting fixtures in a pole barn for the horse stalls.

What I'm looking for is the type that is dustproof/explosionproof (has a thick glass lens) that screws on to an attachment (surrounding the incandecent bulb) that slides over a common pigtail socket suspending from an octogon with center hole cover in the ceiling allowing it to swing if bumped.

I've seen them all over the place and have them in my own barn, yet nobody can remember who makes them or where they got them.

I have tried all the supply houses, but they look at me like I'm an alien, lol.

Anybody have a listing or link?

thks,
Greg