Price listed is for 20 preset stones. These are olive faceted acrylic rhinestones preset in silver cinch mounts. The rhinestone has a faceted top and back, and measures about 4mm (probaly 16 or 17ss). The setting measures about 7mm by 5mm. You should be able to open the setting and replace the stone should you want to. However, the settings were not meant to be opened and closed multiple times and doing so may result in damage to the setting.