Love it. My teeth are happy, my dentist is happy. An unexpected benefit is that it helped with my sensitivity to cold. It would be helpful if, in the instructions, it is explained not to charge for longer than about 4 hours and only every few months. If you leave it in the charger overnight (as I do with most chargers), there is a risk of melting the connection. Fortunately, customer service was wonderful, and I am able to continue to use this product. Product gets five stars; poorly written instructions get one.