Holmes 7 Twin Window Fan, HAWF2021-U

The Holmes Twin Window Fan is specifically designed and safe to use in a window. This product comes with two 6.5 inch blades, multiple speed settings, and a built in extender screen to help secure the fan into the window. This product can fit into virtually all double hung and slider windows and can also be used with a window screen in place.
Customer Review: Good Fan At a Good Price
I bought 3 of these fans to help move air in the lower areas of my home. They do a great job, I have run them non stop all summer, and the motors keep on going.. No issues at all. A good fan that moves allot of air, and takes a beating too..
Customer Review: light weight, efficient, and a little noisy
This product is easily moved around, as it is light weight, and fits the window , very well, as it has an adjustable side. The main negative I find, is that it is noisy. It has a loud "whinney" type noise. So, if you're going to use it to bring in the cool air for just a while, then turn it off, it is great. However , if you are going to allow it to stay running while you sleep, it may take some getting used to. All in all, I find it efficient and an inexpensive way to cool the room or several rooms. It works just as easily as an exhaust fan, when turned around.