15 Silicone nano tips designed for regular RegenPen use. Cartridges should be replaced after each use. Each silicone tip is .08 MM. This means the depth of penetration of the ingredients Please note that if you are experiencing redness or irritation with the daily cartridge, you must change the amount of pressure you are using and do not use it on the same place for more than 3 seconds. Use the Repair Serum or HA3 for optimal results. Cartridges are to be used with the RegenPen - RegenPen is not included #Anti aging #Skin repair #Wrinkle reducer