My brother sent me an email reguarding these about a year ago. They installed them in the ethanol plant where he works.

http://www.lithonia.com/products/groups/Fluorescent/I-Beam/default.asp

I haven't talked to him about them since. Will have to see what he says. Hope they work good as I hate flourescent lights. I hate the light they produce and I hate replacing bulbs/ballasts. We had a lot of trouble with the 8' units in our shop previously. Either way, not going to stick any more money into a 30 year old shop that we've outgrown.