Roaman Portable Electric Water Floss Teeth Cleaner uses intensive water jets to remove residuals stuck between the teeth, or between the teeth and gingiva. The machine has three modes. The Normal mode is for general teeth, the Soft mode is for sensitive teeth and new hands, and the Pulse mode is for deep cleaning with alternate intensity of water jet. Users should first open the cover on the machine’s top and pull out the injector, then insert the injector into the groove next to it. Afterwards, open the lid of the water tank at the bottom of the machine and pull up the tank to the mark. Pour water into the water tank and then cover the lid. Now you can aim the nozzle at the teeth or crevices between teeth before pressing on the cleaner.