A single brush head can be used for 6 to 12 months. This set includes a replacement brush head. The number of bristles has increased from 768 in the third generation to 1908, designed to enhance teeth cleaning and gum massage. An additional brush head is included based on external testing. Four one-touch modes: A. Strong mode for intense cleaning B. Medium mode for comfortable brushing C. Gum massage mode D. Whitening mode This U-shaped toothbrush is designed for easy use—gently bite into the brush head and move it side to side to achieve a 360-degree clean. Utilize vibrations to thoroughly clean teeth with minimal effort. The design allows for multitasking during your routine. The electric toothbrush helps maximize morning efficiency. The whitening mode supports hands-free operation.