2021-UPGRADED WATER FLOSSER. Newest dental flosser is upgraded with 5 settings of water pressure(range from 20-110psi).This design allows you customize your own teeth cleaning experience. Another outstanding breakthrough is :The gravity ball added at WATERPROOF DESIGN. IPX7 waterproof design is adopted for both internal and external of the machine to provide dual protection, which prevents leakage and allows the water flosser to be used safely for shower in the bathroom. LONG LASTING BATTERY. Rechargeable oral irrigator with powerful 2500Mah lithium battery is able to last for 10-15 days once fully charged. The USB interface charging is applicable to a power bank, phone charger and PC.etc.