Features: -Equipped with an advanced millimeter wave sensor that can sensitively detect hand movements. When you bring your hand close to the sensor, the nozzle will quickly release soap within 0.25 seconds.-With a light interactive reminder function for washing, the little yellow duck's eyes will flash for 15 seconds to promote children's correct hand washing habit.-Built-in rechargeable battery, charging only takes 2.5 hours, and can be used more than 10,800 times when fully charged, ensuring an ultra-long service life of 100 days, and only needs to be charged 3-4 times a year.-It can hold any type of hand soap, and before use, the liquid soap must be diluted 5-8 times with drinking water (soft water). (Note: the liquid soap must not contain f.