Ultrasonic Dental Scaler For Teeth Tartar Stain Tooth Calculus Remover Electric Sonic Teeth Plaque Cleaner Dental Stone RemovalDear friends, our product is very hot selling,now let me answer some questions from the buyers.Q:The product doesn't vibrate after turn it on?A:The product adopts ultrasonic technology, and the product itself won't vibrate after it is turned on.You need to install the cleaning head, use a small wrench to tighten the cleaning head.When the product touches hard objects such as wrenches, teeth, etc, it will make a sound, indicating that the product is vibrating.No sound or vibration when the product touches soft objects such as skin and gumsQ: Cannot be turned on, cannot be charged, doesn't vibrate, missing accessoriesA:When you encounter similar problems, please don't open dispute and don't give bad feedbck in advance.Please contact us Immediately, if the product has quality problems, we promise to resend a new product for you.Q:No effect after using the product?A:The vibration frequency of our product is within the safe range and will not cause damage to tooth enamel.Please charge the product for 2 hours to maintain sufficient power.Some buyers do not have a serious plaque problem and it is hard to see it by eyes.There is a lot of saliva in the mouth, and the shed plaque may have mixed with the saliva.Please brush your teeth after use.Keep using it and your teeth will be very clean.Additional Notes:1.The product preset 10 minutes automatic shutdown function to prevent overheating2.The product cannot be turned on during charging, please unplug the charging cable, then long press the power button for 3 seconds to turn it on