Design for maintaining HVAC systems, the Model FS-245-B FILTERSCAN Wi-Fi air filter monitor utilizes patented differential pressure methods to monitor air filter clogging status. Providing local, text and e-mail alerts, it is compatible with single and multi-speed blower HVAC systems and most VAV (Variable Air Volume) systems. Features include automatic air filter monitoring, local visual and audible alerts, internet-enabled notification system, configurable text and e-mail alerts, and easy Wi-Fi network connection. Operating from a 6 Vdc adapter or four AA Batteries - Model FS-245-B and an operating temperature range from -40ºF to +257ºF. For more details, visit http://www.cleanalert.com/filterscan.html.