TimeMist Settings Dispenser offers a sleek design and simplified user-interface so you can easily maintain delightful aromas throughout your environment. Top-hinge accessibility allows fast and efficient servicing. Unique, magnetic lockable dispenser ensures secure and continuous fragrancing at intervals of 7.5, 15 or 30 minutes. Dispenser also features innovative, light-sensing technology that ensures the dispenser runs only when needed. For the day-only mode, the light sensor operates the dispenser at designated intervals as long as your light is on. When the light goes off, the light sensor turns off the dispenser. The reverse occurs in night-only mode. Versatile design lets you choose to use two AA batteries (sold separately) for one year of operation or four AA batteries (sold separately) for two years. Indicator lights alert you when to replace the batteries and the scent refill. Energy-efficient design reduces operational spending by up to 75 percent.