Instruct: Classify an Amazon review into positive or negative sentiment.
Query: Not a great purchace

These are supposed to be the correct replacement heads for my toothbrush. They have the same name and look EXACTLY like they should. But when I attached one of them, I noticed that the fit was not right- it was on there, but it was way too loose. And that was after a good 5 min of hurting my fingers, trying to squeeze the color ring onto the bottom of the head... I got it on there but not without difficulty. I am still using the head on my toothbrush... only because I can't afford another one right now. It came halfway off the base while brushing yesterday... and the piece with bristles is starting to detach from the stem. Don't think it'll last much longer. This product is an imposter!