Something you should know..... snap jewelry necklaces, snap jewelry bracelets, snap jewelry earrings and snap jewelry rings come in 2 sizes, 12mm (small) and 18mm-20mm (large). All the 12mm snap jewelry and snaps are marked as 12mm in the description and their item numbers starts with a 12- .  All the other snap jewelry will fit the 18mm snaps or 20mm snaps and their item numbers start with an 18 or 20 or both.  Some may have a larger number only because the snap is larger than the base but they will fit 18mm or 20mm snap jewelry. This will be helpful when selecting snaps for your snap jewelry bases. 

If you have snap jewelry and you don't know which size you need, the 12mm snap or base size is a little bit smaller than a dime and the 18mm-20mm snap or base size is a little smaller than a quarter.

https://www.snapjewelryonabudget.com/ - SnapJewelryOnABudget