Product descriptionjarden hawf2041 window fan: in with the good air, out with the bad air. The holmes twin window fan operates quietly & efficiently by taking in fresh, cool outdoor air & exhausting stale, warm indoor air. The manual thermostat sets & maintains the ideal comfort level. The dual blade operation has independent controllable, reversible motors with 3 speed settings. The motors are water-resistant & are safe to use during rainy weather. Designed to fit most double hung & slider windows. 1 adjustable accordion extender screen & 1 5-inch removable panel help secure fan in larger windows. The product comes with a 3-year limited warranty.designed to fit into most double hung & slider windowsadjustable extender screen & bonus extender panel help to secure fan into larger windowsindependent electronically reversible motors allows for air intake, exhaust, or air exchangeplug in the power cord into a 120 ac outlet. Refer to the pdf attached below in technical specification for user manual.troubleshoot- if air does not seem to be blowing in properly adjust airflow directional switch to intake. Note-for slider windows set the fan vertically in your window opening with the left side of the fan situated on the bottom & the built-in extender panel on topcomfort control manual thermostat sets & maintains ideal comfort leveldual blade operation with independent electronically reversible motors; three speed settingswater-resistant motors are safe to use during rainy weather; designed to fit most double hung & slider windowsadjustable extender screen & extender panel help secure fan in larger windows; 3-year limited warrantydesigned to fit windows with minimum openings of 25 in wide & 12 inches hide; with extender panels, can extend to width of 35 in.