It's like round with a hole in the middle and that's the reason why I call it a hair donut. This thing underneath is becoming hot. It's very usefull when you're having short hair, if you put this in your hair, it makes your hair look longer. But it's also very trendy if you do it with long hair. You can make a braid of the hair what remains. I've got one and my hair is not very long but also not short. Rosa's hair is short and she has one too. It looks really cool! You can buy it in a drugstore or shops like Primark or H&M.
Lots of Love,
Charlotte & Rosa