FRIENDLY TO SENSITIVE GUM F5027 water pressure range starts from 10 PSI and with a professional maximum 90 PSI. Sensitive teeth users, the olders, orthodontic users can all find their most comfortable water pressure in F5027. MOST POPULAR FLOSSING MODES 4 flossing modes including Custom Mode. User can DIY their own custom mode from 8 levels of water pressure, considering the variety of oral conditions. USB-C Charging and IPX7 Water Resistance Built-in rechargeable Li-Ion battery, charged by USB Type-C cable. Charging port is protected by soft rubber cover. Internal and external double IPX7 waterproof protection is safe to use in a shower. 180ml Lightweight Water Tank F5027 water tank has proper volume and is easy to carry. Detachable water tank and flippable refill hole size are easily refill and clean. Use with water, mouthwash or anti-bacterial rinses, as recommended by dentist or hygienist.