iActive SG910 Intelligent frequency sonic electric toothbrush with 3 brush heads. Strong (35,000 beats / min), weak (23 000 times / min) two kinds of brushing modes for different population needs. Smart 30 seconds to remind, 2 minutes time, to develop a good habit of brushing science. Highest level of super IPX7 waterproof, can work underwater for half an hour. Low energy-saving, two AA batteries(not included) work 150 days. Presented three brush heads, environmental health, three months to replace one, available for one year. DuPont bristles.