Plug & Play Module - Multi Speed And TimerThe Multi Speed with Time Delay allows you to select the proper CFM settings to satisfy ASHRAE 62. 2 continuous ventilation requirements. The fan runs continuously at a pre set lower level, then elevates to a maximum level of operation when the wall switch is turned on, or when the SmartAction motion sensor or condensation sensor module is activated. A High Low delay timer returns the fan to the pre set CFM level after a period of time set by the user.