... the brush attachment and the base (which doesn't sound like much, but trust me
These don't fit my Sonicare--there is a gap about 3mm wide between the bottom of the brush attachment and the base (which doesn't sound like much, but trust me, it's plenty). When I turned the brush on with the head attached, the vibrations under the ill-fitting head produced an insanely loud buzzing, rattling sound. When I tried to take it off of the brush base, it was jammed and I had to seriously whale on it to get it to come off. It's not worth the shipping to return it. These are a hard NO.
Rating: 1 stars