Have you ever noticed that you can’t ever find the right replacement brushes for an electric toothbrush? Even when I’ve bought the only brand of toothbrush on the shelf, and the only replacement brushes are hanging next to them, and they’re the same brand, they still don’t fit. And they don’t have model numbers, where you can say, oh, I have an M2 toothbrush and here’s an M2 replacement brush. I’d say it’s a conspiracy to get you to buy a new toothbrush instead, but why would they go to all the trouble of making the replacement brushes?
Seinfeld moment
They only have to make a few just for show, since the only ones they ever sell get returned.