Works but mechanism break down faster than brush decays
So... you get what you pay for with these replacement brush heads.  They're amazing when they work, which is almost all the time.  Just be careful of the brushhead and don't be rough with it.  I notice the mechanism inside the toothbrush tends to break down or stop rotating before I even wear down the actual brush itself.  This occurs if you wipe down your toothbrush with a a towel to stop dripping, the force of wiping can hurt the mechanism inside.  You don't want to be just moving your toothbrush around in your mouth thinking that it's working because you're fooled by the buzzing noise.  If it does happen, just brush normally until it wears down or throw it out and put on a new (given the price range).
Rating: 3 stars