The Serum Infusion Head is compatible with all Soniclear models except Soniclear Classic. SERUM INFUSION HEAD allows you to harness the power of sonic movements to apply serums and creams onto the skin for maximum efficiency. The Problem: The majority of the skincare products you apply with your fingers are either absorbed by your fingertips, settle unevenly onto the skin or evaporate before they have a chance to start working The Solution: When skincare products are applied to the skin through a sonic delivery system like the Serum Infusion Head, they are dispersed more thoroughly and more evenly so that they can FINALLY begin working for you. Sonic movements at hundreds of times per second help the beneficial ingredients in your skincare products “get to where they need to get” in the  epidermis instead of settling on the surface of the skin. You will be amazed at how much better the products you are already using, start working for you. 6 operating speed settings – When used with the Soniclear ELITE 3 operating speed settings – When used with the Soniclear PETITE Soniclear brushes are the world's first antimicrobial sonic skin cleansing brushes that help to guard against stain and odor causing bacteria. The Serum Infusion Head is compatible with all Soniclear models except Soniclear Classic. 391