Sterile Disposable Needle Heads Refills include sterile needle heads to attach to your Micro-Infusion device. Each needle head is to be used one time per treatment, and disposed of after each treatment. This minimizes the risk of infection and unnecessary damage to the skin. Use one full serum ampoule per treatment. Please keep in mind that not all serums are suitable for micro-infusion. Some may cause irritation and should be avoided! We have developed our potent serum ampoules that are perfect for Glov's micro-infusion system. They are formulated to have a low risk of irritation and with no fragrance.