Way too fragile.  Not a quality replacement head.
The internal mechanism that keeps the brush head on the toothbrush motor breaks far too easily. I’ve never been a hard brusher so I know I’m not putting a lot of pressure on the head.  I’ve also never had this issue with any of the other brushes I’ve purchased as replacements but I’m going on my third head in just over two weeks.  All have broken in the same spot.
Rating: 1 stars