2 pack of Replacement brushes for sensitive skin for use with the Hydrasonic Cleansing System. What It Does Durable snap-on brushes for quick setup and cleaning. HydraSonic Sensitive Skin Facial Brushes cleanse 14x better than manual cleansing. Ideal brush heads for gentle cleansing of sensitive to dry skin. Helps to minimize appearance of large pores and make skin look and feel noticeably smoother.