Product review (5 stars): Perfect replacement for the 40000 series fans!
This fan is quieter than the original by far!!!! The fan blade was unfortunately installed on backwards but I pried it off, flipped it over and pressed it back on. Be careful prying it off though the plastic is fragile and bends really easy. I used a small piece of wood and slid it under the fan blade then used a small screw driver to pry it up then to press it back on I set a 7/8" deep well impact socket to on the center of the fan blade (1/2" drive side facing down) and light tapped on it with a mallet (hammer). I pressed it on there a little further than the original due to the blade being really close to the filter and I wanted the blade recessed to pull more air in without pushing air around below the hood. I recommend this product so far. We have only had it for a couple days but the quietness is wonderful. The last fan sounded like a jet engine and this is a Prius! Metaphorically speaking of course