For extra gentle cleaning, especially for kids under three, use a round brush head for their mouths. Soft bristles that are especially gentle on the gums Compatible with Oral-B's Disney Magic Timer App Included are four Disney Frozen stickers. Always use the built-in timer to maintain the proper cleaning duration of two minutes. The rechargeable battery has an eight-day lifespan. Add four stickers with Disney Frozen themes to the brush's handle to make it uniquely yours.