This electrically reversible twin window fan with remote control from Lasko, comes fully equipped and ready to meet just about every need. Two independently controlled fan motors allow for operation in three ways; intake to bring the air in, exhaust pushes stale air out and exchange which allows one fan to operate in exhaust while the other operates the intake mode. The digital thermostat senses room temperatures and turns the fan on or off automatically to maintain the comfort level desired. Expander panels provide a custom fit for most windows 24 inch to 32 inch wide and 12 inch or higher. 1 year limited warranty.