Ordered for my son's toothbrush, fits perfectly.I really do like the toothbrush, but the brushes that came in the starter set split almost immediately. There really isn’t much of anything worse than a mouth full of bristles when you’re just trying to brush your teeth.I decided to try a replacement set to see how they held up before calling it quits on the setup. These actually fit better than what came with the original set. They click into place which never happened with the first ones. If they last me a year like they should I’ll be happier than I was.I hope this is helpful to someone. ***Edit: 21 July 2020. I’m down to the last of the four that came with the replacement set. Two split, one just broke off at the end of the head. At a guess I’d say it took a little over a month. I ordered another set. I really do like the toothbrush. But I’m looking. This is really high maintenance so far. ** Edit 12-Aug-2020: I’ve already gone through two of the four I ordered in July. They’re still splitting. I have already chosen a replacement. Buying one more set of heads would put the cost of the heads at more than the cost of the initial set. It’s just not worth it. I’ve never come across anything like it, but maintenance that’s over and above your initial investment is not sound business practice. I also apologise. I’m not a fan of negative reviews and haven’t had to write many. In this case I felt compelled.I hope that my experience is out of the ordinary. At the same time I don’t think they see my name on an order and pick mine out of the reject bin. **1-Sep-2020 The last brush of the last set I ordered fell apart leaving me with yet another mouthful of bristles. I’ve ordered another toothbrush.I also hope this is helpful to someone.Works great! Fits perfect!Da SweetLF schon länger keine Ersatzbürsten mehr liefern kann, habe ich diese Bürsten gekauft - sie passen bestens - ich bin froh um den Tipp!Very happy with the teeth cleaning system. Not so happy that replacement brushes are not available in Australia and have to come from the US.