Twooth® Timer is the award-winning, mom-invented tooth brushing timer to help children & adults brush their teeth for the recommended two minutes. Tooth decay is the most common, chronic childhood disease and it is preventable. Good dental hygiene is a major factor in the prevention of tooth decay. Using Twooth® Timer makes brushing fun, helps improve dental hygiene which lowers dental bills, and reduces stress for parents/teachers. Because even small children can do it themselves, they take more responsibility for their dental hygiene and feel a sense of accomplishment when they brush their teeth for the full two minutes. More brushing & less fussing. It's so simple to use, even for a toddler. Simply turn the top clockwise to the ‘2' and brush till the bell rings. Conveniently sized to fit on counter tops (without taking up much room), in most medicine cabinets and drawers: 3 ¼" H x 2 ¾" W x 2 ½" D. No batteries needed.