After installing and trying out the different speeds, the two outer fans petered out, like within minutes. Admittedly, the one I bought was refurbished or whatever, so maybe a new one is good. I have nothing against the seller, they were great and even let me return it free of charge for a full refund. That said, don't buy this thing.

Very weak

The media could not be loaded. First off, the fan has a locking tab on the top, and it is quite pronounced, making it impossible to create a full seal because it creates a 2cm gap between the fan and your window. After one week of sparing use, my fan began to make a shrill clicking sound and rattle. The bearings on the fan are bad, and the fan blades are made of a poor plastic material - after a few days in temperate Seattle weather it warped and has become contorted. This is a horrible product. Do not expect it to be designed well, seat well in your window, or run reliably and quietly. It quite simply is not even remotely usable.

is only work for a month

Hardly has any power to it at all

p.o.s. this fan moves little or no air, a big waste of money. buy anything else, but DO NOT WASTE YOUR MONEY

Not reversible.

Sent it back. one speed only is annoying and it is loud!

One fan stopped working after 10 months of light use. Do not buy.

Already broken