Electric Sonic Dental Calculus Scaler Oral Teeth Tartar Remover Plaque Stains Cleaner Removal Teeth Whitening Portable with LED 0ral irrigatorAttentions 1. Install the tip and tighten it ; 2. Long press to turn on off the device; 3. Choose a working mode; 4. The equipment preset 10 minutes automatic shutdown function to prevent overheating; 5. You need to unplug the charging cable before turn it on and use; 6. The device works when it touches a tough thing like teeth and metal,if you use it on the skin or other soft thing,it will not work.