A single brush head can be used for 6-12 months (this set is also equipped with a replacement brush head). The number of bristles increased from 768 in the third generation to 1908. In order to better brush teeth and massage gums, the external test also adds a brush head. Four modes of one key operation: A. strong mode, strong brushing B. Medium mode, comfortable brushing C. The way of gum massage D. Whitening mode of tooth whitening.This U-shaped toothbrush, you just need to gently bite it, and then swing left and right to clean the toothbrush 360 degrees. Gently bite the brush head and use the sound wave vibration to clean your teeth in an all-round way. You can make up while brushing your teeth or wear clothes. This electric toothbrush will make your morning time more effective. When you use the blue light whitening mode, you can completely free your hands.