It's Much Better to Go With Oral B, not These Generic
I found these generic replacement heads to be substandard.  The bristles came out very easily and were sort of sharp.  Also, when the brush was running, the generic head wobbled on the spindle...made a lot of noise.  It didn't seem to fit securely and I thought it might actually come off or come apart in my mouse during use.  I used only one and threw the others out.  Cannot recommend.
Rating: 1 stars