IBM UPS Office Professional OP500

Today a friend of mine who is an auctioneer had another one of his estate auctions. At the auction in one of the box lots was a UPS. I have always wanted one but never got around to getting one. I had to help clear the house out and saw it prior to auction start. I thought he would sell it individually but I guess not. Anyway the box lot went for a whopping $1. The UPS seems to be in good condition, however I know nothing about them. It didn't come with a manual. I'm leery about plugging the computer into it not knowing anything about it. I tried looking for info on it on the Internet but couldn't find much. I tried IBM's website but it didn't have anything. Do any of you know anything about this particular UPS?

I know we have a couple of IBM UPS units at the office connected to each of our AS/400 systems. We may have some connected to some of the other emergency systems too? I don't know the model numbers but I do know they are IBM. When I get to the office I will check for you. If I have that model, or one from a similar series I will let you know.