I bought this at Costco last year. The box says 7M (24cm), and I bought it without trying it on... but the contents were 6M (23cm)! I'm so bummed. I've already cut off the tag, but it's unused. It's a 6M (23cm), so please make sure you understand that. I will ship it in the original box. However, please note that the box is labeled 7M (24cm). The box is in good condition, but anyone could try them on, so please refrain from purchasing if you are very particular about this. Please read my profile before asking questions or making a purchase.