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. Note: 1. Please allow 1-3 mm error due to manual measurement and 1-3g weight error make sure you don't mind before ordering. 2. Due to the lighting of the photos and the difference of monitors, the pictures may not reflect the actual color of the real item. Please make sure you don't mind before ordering, thank you! About Shipping: 1.please pay attention to your delivery address such as: name, street, house number, doorbell/email without name, etc. is correct, or the order will not be delivered correctly. 2.All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances. 3.During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours Hope you have a pleasant shopping experience!