YOU GET WHAT YOU PAY FOR !!!
The price was great and we had had great results in the past with previous suppliers (2) of these brush heads for the Sonicare toothbrush. The first supplier was the best. The second was "OK" but this time, that was not the case. As you use the toothbrush the brush head vibrates out and needs to be re-inserted - not quite what you want.  Given this problem and the fact that we are vacationing we went to Sam's Club and purchased OEM (Phillips) brush heads in a set of 6 for $40. The cost of the aftermarket brush-heads in a set of 8 was somewhere in the $20 area.- bottom line, in this case "YOU GET WHAT YOU PAY FOR"
Rating: 1 stars