One of the latest crazes for coloured bracelets has got adults so worried that some schools are banning them.
A pack of six can cost as little as 75p and to loads of you they're just fashion accessories, but some adults think the bracelets are more sinister.
That's because each coloured band has a meaning. In some places, for example, a purple band means kissing someone.
But some people think it could put you under pressure to do things you may not want to do.
Some schools are banning pupils from wearing the bracelets in school and now a politician has got involved too.
MP Mary Creagh wants shops to stop selling the plastic bands to anyone under the age of 16.
"I think it's probably a bit of fun if you're over 16, but it's not appropriate for very young children," she said.
But lots of shops Newsround's spoken to have said they don't plan to stop selling them because they're made and sold as bracelets, nothing more.