Panasonic Cordless Water Flosser with Ultrasonic Technology, EW-DJ66 Series 600, Removes up to 99.9% Plaque. Ultrasonic technology carefully removes food debris, plaque, and bacteria in areas your toothbrush often misses. It's clinically proven to be 2 times more effective than string floss. With 5 levels of water pressure, you can find the best setting for your gums. The 200 ml water tank holds enough for up to 60 seconds of use. A 1-hour USB-C charge gives you up to 10 minutes of battery life.