LORDE + BELLE : RegenPen Cartridge 15 pack 15 Silicone nano tips: Sensitive, Regular or Weekly 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. Use the Repair Serum or HA3 for optimal results.