Anticipation, the brush heads fit exactly, since it should have given seemingly loud individual reviews before complications. But that was certainly more to incorrect orders at a reasonable price without taking into account the design and appearance of the brush heads.
There is for each brush head respectively a colored ring which is pushed onto the lower end of the brush head. In order for a hygienic use of sonic toothbrush by several people with their own brush head is possible.
For quality of the bristles there is not much to say, the bristles are ergonomically cut, very well rounded, of medium hardness and remain quite a long shape.
However, the dimensional stability depends greatly on the applied pressure of the respective user in brushing. The pressure should be relatively quite low in this sonic toothbrush, then to get a little further than the recommended change intervals it say.
Conclusion: As the owner of a sonic toothbrush from Philips is indeed getting a good product but also have to live with the rather high price. Cold comfort, a good Oral B manual toothbrush also costs around four euros ...
Health and a radiant smile who hold their price.