Use the Maestro countdown timer switch on DC or high-efficiency bathroom exhaust fans to reduce mold and mildew. Save energy by using the Maestro Countdown Timer in closets, attics, basements, and other low-traffic areas to ensure a light or fan is never left on for a long time. Use the large tap switch to turn the timer on and off. Softly lit LEDs indicate the time remaining before turn-off. Coordinating Claro wall plates and accessories sold separately.