Suncourt ThruWall 2-Speed Room To Room Fan for Indoor Air Ventilation IMPROVED AIR CIRCULATION - Circulate air from one room to another. Perfect for work-shops, work-spaces, craft stations, rooms without windows, or any room that needs improved air circulation. TWO-SPEED OPERATION - The ThruWall Fan features a two-speed motor so you can customize airflow to meet your needs. EASY INSTALLATION: The ThruWall can be mounted in any normal drywall or paneled stud construction wall with a 3-3/4" to 6-1/2" total thickness thanks to the telescoping metal sleeve. HARDWARE INCLUDED: Includes #6 screws and wall anchors for ease of installation. GREAT FOR ALL SEASONS - Whether you are trying to keep things cold in the summer, or things warm throughout winter with the simple flick of a switch you are bouncing between heat and cool.