The Lasko electronically reversible twin window fan will keep you cool both day and night. Two independently-controlled motor fans operate in three ways - intake to bring in fresh air, exhaust to push out stale air, and exchange to combine both operations. The digital thermostat senses room temperature and turns the fan on or off automatically to maintain the comfort level of your choice. It fits most windows (double-hung, casement or sliding) from 22 inches to 32 inches. The expandable panels of this fully assembled unit provide a custom fit for your window space and the slim profile ensures that the outdoors is still within view. Product Highlights

• Smart Cooling: Two independently-controlled motor fans operate in three ways - intake to bring in fresh air, exhaust to push out stale air, and exchange to combine both operations.
• Digital Thermostat: The digital thermostat senses room temperature and turns the fan on or off automatically to maintain the comfort level of your choice. This reduces energy use and can reflect on your electric bill.
• Special Features: 3-Speeds available at whisper quiet operation, making this perfect for nightly use in your bedroom. Easy to read digital display with adjustable brightness makes creating your settings a breeze. You can also use the included remote control and set a timer.
• Space Saving Design: This slim design won't bulk up your window space, no difficult wall installations or take up space on your floor. Simply designed so you can spend more time enjoying and less time setting up.
• Dimensions: (4.25"L x 21.69"W x 10.23"H) 8-lbs. Expanding side panels fit windows from 22"- 32" wide and 12" plus long. Fits Most Windows: Double Hung, Casement, Sliding.
• Maintains room temperature and ventilation
• Window Mount option to establish a firm installation
• Equipped with a high-quality motor to ensure a whisper-quiet operation
• Exhaust: Both fans push stale air out
• Exchange: One fan brings fresh air in and one pushes stale air out
• Easy-to-read digital display with adjustable brightness
• Digital thermostat senses room temperature and turns fan on or off
• Remote control included (batteries NOT included)
• Fully assembled and ready to install in your window
• Expander panels for a custom fit
• Slim profile to maintain outside view
• Blue Plug patented safety fuse technology
• E.T.L. listed