Review on 3-Pack of Genuine DiamondClean Replacement Toothbrush Heads by Philips Sonicare - White, HX6063/64 by Robert Bridgewater

These brush heads do their job perfectly. While your results may vary, here's my experience: I brush with Sonicare twice a day. sometimes on a 2 minute cycle, mostly on a 3 minute cycle. I have found that these nozzles last a little longer than the recommended replacement window. In rare cases, the blue "indicator" will start to disappear within the first two weeks. but then, almost immediately, it begins to go away - quite abruptly. So while the blue indicator bristles can be a useful reminder to change brush heads, I believe you have a pretty long grace period to keep using them. As a side note, I find that using the sterilizer that comes with some of the Sonicares that use these heads causes the blue indicator lines to go away much sooner than usual.