Review (1/5): water WILL get into the unit - a waste of money
My dentist recommended this toothbrush. I didn't want to pay the exorbitant price for the plug in so I purchased this unit. We use rechargeable batteries in my house so replacing the batteries would be no big deal. After a week of use, it stopped working. Thinking maybe I had defective batteries I replaced them. The toothbrush worked on and off for another 2 weeks then completely stopped working. Phillips did agree to send me a new one but unfortunately, that stopped working in just a few days. Water getting into the battery compartment is the problem, no matter how careful you are.
If you don't mind spending 100+ dollars, buy the plug in variety as I really did like how it cleaned my teeth. Otherwise, skip it completely.