This is the second type of oral irrigator I have purchased. The first one was an Oral B, had to be plugged in, and was inoperable after five months. I had a design flaw with the plug-in charge system which allowed the electrical connection to get wet and it became inoperable. The Panasonic is much more user friendly, and since it operates on batteries, is not a pain to have on the sink top. Most importantly, it works very well, has lots of energy to pulsate the water, and I love it!