The 12" Ultra Force Window Fan employs the Comfort Watch™ Thermostat to keep you comfortable even when the temperature fluctuates. With the added convenience of an electrically reversible motor, this fan gets the job done with ease.Features: * Three, Whisper-Quiet Speeds * Lighted, Comfort Level Indicator * E-Z-Click™ Expander Panels for a Safe, Custom Fit * Concealed, Rear Cord Wrap * Fits Windows 24" to 37" Wide and 15" High and Larger * Fully Assembled * U.L. Listed.