Air King's 9155 16" window fans bring fresh air in or exhausts stale air out of residential settings and are powerful enough for light commercial use. The Air King 9155 window fan features a powerful and durable motor that provides the needed amount of air movement. The fan can be set for intake or exhaust and mounts into windows 26.5 inches to 34.5 inches wide with a height of at least 22 inches. The special Storm Guard mounting system allows the fan to be installed in front of the window so that in bad weather the window can be closed behind the fan without having to remove it. Constructed of impact resistant plastic for years of reliable and durable operation. ETL listed and complies with OSHA requirements.