Yes, they fit on the ProtectiveClean, but these heads are not very gentle. These would be much gentler, they simply reinogen just as well, much gentler.
Philips Sonicare S Sensitive
Philips Sonicare Sonicare Sensitive (12 x)
The brushes tested by Kassensturz were counterfeit. The original brushes are fine. Kassensturz had to backtrack and publish a correction on its website (see "Addendum of 10 December 2025"):
https://www.srf.ch/sendungen...
Yes, the toothbrush heads are compatible with the Philips Sonicare ProtectiveClean HX6851/53. The A3 Premium All-in-One brush heads fit all Philips Sonicare toothbrush handles, including the ProtectivClean series such as HX685x models.
This is due to the fact that we were able to purchase a much larger quantity of the white version with corresponding conditions. As a result, we can currently sell the white version at a much more favourable price.