....One thing I did not mention that I should thow out there for other's planning to use one of these. Understand that moving that much air brings suction. I've had a few unplanned "trims" of some chunks of fan leaves, I added a grill, it doesn't help much. I mounted mine while I was growing in the cab so it's not in it's proper place at this time. It's hanging from the celing, later it will be mounted behind the opening in the reflector so it will be out of the way. That's the little wannabe food processor in the upper right corner being used to cool a CHM bulb. 4" and I think 110 cfm.....can't remember the exact cfm #. With it, I can keep a 400 watt CMH bulb 6 inches from the tops, at 4 inches, I had a little light burn.