Once started, the device automatically shuts off after 8 hours, restarting at the same time the next day8 hours on, 16 hours off. No water needed as it contains natural essential oils that diffuse into a mist through microscopic holes in the vibrating plate. Battery operated for placement anywhere. Each refill lasts up to 45 days on the lowest intensity setting. Batteries included. Scent: Lavender & Almond Blossom; Physical Form: Liquid; Application: Automatic Odor Control; Capacity (Volume): 0.67 oz. Features Contains natural essential oils. Once started, the device automatically shuts off after 8 hours, restarting at the same time the next day8 hours on, 16 hours off. Battery operated for placement anywhere. No water needed as oil diffuses into a mist through microscopic holes in the vibrating plate. Three intensity settings for ultimate fragrance control. Each refill lasts up to 45 days at the lowest intensity setting. Learn more about Reckitt Benckiser Package Includes (1) Diffuser; (1) Refill; (3) AA Batteries