This 9-inch twin window fan is the most practical way to get cool air in your house on a hot day. It features independent motor control for air intake, exhaust, and exchange. It provides a high volume of air movement, and fits windows 24 to 31 inches wide. The fan comes with an adjustable thermostat, three speeds, and feet, so it can be used as a table fan. Additionally, window installation doesn't require any tools, making setup a breeze.