a terrfic item that is handy clever actually works [SEP] this is my second purchase and i cannot say enough about how simple effective this gizmo is at getting little food particles my toothbrush misses it is more fun than flossing and works just as wellno batteries or electricity i fill it up with a combination of mouthwash and water and am amazed at how efficiently it works it is so good that i keep the second one at work for when i get back from lunchmy biggest suggestion though is to buy one for the kids they will love using this little toy before realizing that it is doing something good for them and filling it with plain old water will do just fine too