As an electrician by trade, I can tell you that there should be an info tag with mfg name mdl and voltage/wattage and type... better pictures would help. I didnt see the bulb base in the center of the fixture with the cover removed, which throughs me off. Most fixtures of that size would have mogul base bulbs... about 1-1/2" diam threads where the bulb screws in.
What's the bulb look like? Should be wattage and type on it also.
I agree... low bay style fixture.