My wife bought new toothbrush heads on her way home from work today.
They didn’t fit. She bought the “Oral B IO” heads, but we have a “regular” Oral B toothbrush, not the Shiny Fancy IO design.
And this is after she bought replacement heads last week at another store – which turned out to be “compatible for” a different brand :(
Ugh.
For camping, as you have the iO heads already, get a iO series 2 body as they use the older motor but new heads and the battery lasts about 20 days. Way longer than other iO series bodies. It’s not as good as those either but for camping, meh.
Also, you can buy USB-plugged oral B chargers. Useful for travel