The Tork C515M 15-Minute Spring-Wound In-Wall Twist Timer With A Commercial-Style Metal Faceplate Is Designed to Control A Variety Of Indoor Appliances, Motors and Lights. Automate Factories, Offices or Other Buildings to Save Energy and Money Using The Simple Twist Knob and Reliable Mechanical Timekeeping. Fits Into A Standard Electrical Box For In-Wall Mounting. Designed For SPDT Switch Type On Indoor Loads Such As Ventilation Fans, Lighting, Hvac Systems, Motors, Pumps or Air Compressors.