It works. Could be quieter. The design could be improved, and I would have preferred white, not putty-colored. I bought this because it was the largest-diameter window fan that I could find that would fit my window. I use it at night in the summer to pull the hot air out of my attic and pull in the cooler evening air, thus keeping my whole house much cooler during the day. (I'm one of the last remaining air conditioning holdouts.)