Review on AquaSonic Black Series Replacement Brush Heads 2-Pack - Optimal Electric Toothbrush Refill Heads by Cindy Payne

Reasonably priced product, well packaged but most important aspect, compatibility, not up to date. I bought 2 packs of 2 replacement heads. As I twisted the head off, I noticed that the brushes "skipped" with each squeeze while brushing. It just stops moving, as if the brush head weren't aligned with the toothbrush gears (for lack of a better explanation). The small motor still runs, but the brushes don't move. I tried the second one, thinking I might have an incorrectly made head, but I also had the same result. I didn't open the 2nd package as I want to return it and get my $$ back. Maybe I just got a bad batch, or maybe it's bad design. I do not know.