I had the opportunity to test this product and I am very pleased with it. My daughters (5 and 3 years old) already have electric toothbrushes: one child-friendly version that vibrates slightly, and the other has a standard one with a rotating motion. I use a Philips Sonicare myself and use these brush heads on my brush to brush the children's teeth (or to finish brushing them). The size is perfect: it actually looks like a manual toothbrush, but with sonic movements. The children found it took a little getting used to ('it tickles!'), but they tolerate it very well. The teeth get nice and clean, and the brush head feels like it stays hygienically clean for a long time (something I had quite a lot of trouble with with the competitor). If the children's toothbrushes prove insufficient, I will switch to a Sonicare brush for the children as well. I also noticed that Philips Sonicare has very nice children's brushes on which these heads, with the quieter version, fit very well. I am very satisfied and recommend this product.