Likely not their technical name - but I am obsessed. No breakage from pony tails, no bumps. You simply twist these into your hair for a tight bun, messy bun, or pony tail. I use them in the morning when I don't have time to blow dry my hair, or at night if I'm sleeping with my hair wet. My natural hair is VERY straight, but when I twist it up into a bun and insert the swirly twirlys, I can let my hair down a few hours later and BOOM. Perfect curls.
I only use two for my hair type. My hair is long and I have a lot of it - but it's very fine. My thick-haired girls will likely need four.
I buy mine from Fred Meyer (I have a weird obsession with Fred Meyer that we can explore later) and they're Goody brand. About $6 a pack - no need to break the bank on this trick for healthier, bouncier, happier hair, my friends.