30-second smart timer. Shut off automatically in 2 minutes. Reach IPX7 waterproof standard. Adopt sonic technology for high-frequency operation. Brush the teeth at 35,000 strokes per minute. Effectively clean plaque, coffee stain, and more. Fit different demands with 3 modes: super, normal, and mix Support wirelessly inductive charging with an in-built Li-ion battery. Easily replaceable head.