A single brush head can be used for 6-12 months (this set also comes with a replaceable brush head). ^The number of bristles has been increased from 768 in the third generation to 1908. To improve brushing and massage the gums, the external test has also added a brush head. ^Four modes with one button: A. Strong mode, powerful brushing; B. Medium mode, comfortable brushing; C. Gum massage mode; D. Whitening mode for teeth whitening. This U-shaped toothbrush only requires you to gently bite into it and then swing it left and right to clean your teeth 360 degrees. ^Gently bite into the brush head and use the sonic wave vibrations to clean your teeth comprehensively. You can do your makeup while brushing your teeth or get dressed. ^This electric toothbrush makes your morning routine more efficient. When using the blue light whitening mode, you can completely free your hands.