Product review (1 stars): Dangerous sharp edges, then defective fan installation
I installed this product today, and my hands were cut in 4 different places as a result of the thin, sharp sheet metal edges inside.  The 25 year old Broan hood that I removed had 100% rolled edges to prevent this safety issue.  So definitely wear gloves IF you decide to buy this item, and get an updated tetanus shot.  However, after getting thoroughly hacked up, I tested the lights and fans, and the fan didn't work.  When I looked at it closely, the plastic fan blade was so tightly wedged into the hole it was designed to turn within, that the motor could not budge it.  I pried the fan blade loose from the whole, but the fan blade had been bent out of round and still contacted the sided of the hole and made noise. Typical Mexican quality control that Stanley products ran into, and nearly ran their garage door opener business into the ground.  I see other reviews for this product on  the Home Depot website complaining about the fan defect issue too.