Oral-B Sensitive Gum Brush Heads 3ct

I bought an Oral-B iO electric toothbrush at my dentist's office a few months ago after (whoops) leaving my old brush of another brand at a hotel. When I went online to order spare "sensitive" brush heads, I was happy to see a 3-pack at a decent price and picked it up. This week, it was time to change the brush head, and after opening the package (whoops) discovered that Oral-B has different shapes of brush heads, and the one I bought won't fit on my iO rechargeable brush. And it's a couple of months past the return period, anyway. Totally my fault. When I look at this page today, I see that the "COMPATIBILITY" paragraph says which models this product will or won't fit. I'd love to give a rating of "Not Applicable," but since I can't, I felt 3 stars was the least inappropriate option. On the positive side - I was initially apprehensive about the Oral-B's rotational motion, concerned that it might abrade my several-year-old gum grafts, and that has definitely not been an issue. In fact, I believe the Oral-B so far has prevented plaque better than my previous, vibrating brand. Maybe it's a good thing that I left that old brush in the hotel, after all. Now, I'm going to order the correct item for my iO!