Various nail brush caps ⬛︎ Various shapes ⬛︎ We cannot answer questions about the diameter in centimeters. ⬛︎ Sold as a set Please understand that these are used, second-hand items. If you are concerned about this, we recommend purchasing authentic products from an authorized retailer. We prefer to deal with those who can transact smoothly. We do not negotiate prices. If you are okay with simple packaging, please consider purchasing.