Whisper Sense is a single-speed, ventilation fan which is enabled by any of the three following methods: motion on/motion off, motion on/humidity off or humidity on/humidity off. The humidity sensor is adjustable between 30-Percent and 80-Percent RH and factory set for 50-Percent. The fan can be set to run 0.5 to 60 minutes after the motion sensor ceases detection or the humidity returns to the set point. The humidity sensor continues to check that the moisture levels conditions have been met. Complies with States and Municipalities that have moisture control codes such as CALGreen. User-friendly installation-detachable adaptors, firmly secured duct ends, adjustable mounting brackets (up to 26-Inch), fan/motor units that detach easily from the housing and uncomplicated wiring all lend themselves to user-friendly installation. This model also features a double-hanger bar system for ideal positioning.