Because this waterpik must be held vertival for the pump to work, it was impossible to clean the inside of my bottom teeth. Sorry, but a table model is all that will work, which I now have: returned the portable model. Raating based solely on my circumstances!
My dentist recommended I try a water flosser and I love the power and capacity of this one has. It's gentle but does a great job cleaning like floss but even better and without the fuss.