CONTACT US: Login your account > choose "Your orders" > find the order ID > click "Contact seller", We promise to return and exchange products at any time if we are not satisfied within one year. SMART VIBRATING NOTIFICATION TIMER: Built-in smart timer control, 30 seconds interval reminding you to move to the next quadrant of your mouth, and totally in 2 minutes(4 quadrants), which is highly recommended by professional dentists, as a correct brushing way. 4 REPLACEMENT BRUSH HEADS: Comes with 4 replacement brush heads to avoid ordering new replacement brush heads frequently. The bristles are made with DUPONT nylon, Each brush head lasts 3 months so 4 will last for about 12 months. 3 HIGH-PERFORMANCE BRUSHING MODES: Meet Children's Various Oral Cleaning Needs, soft (Please massage for 30 seconds); whitening (It takes 1 minute to whiten teeth); cleaning (30 seconds for the final cleaning). SAFE AND EFFICIENT BRUSHING: 2021 New Upgraded Electric Toothbrush, Speed - Up to 26000~30000 brush movement/min, remove up to 7x more plaque than a manual toothbrush, removing up 100% plaques, Protect every child’s teeth.