Dr. Scholl's NanoTech replacement heads are designed to exfoliate, smooth and buff foot skin, compatible with all Dr. Scholl's Electric Files and Amope devices. The Fine head smooths and buffs for frequent touch-ups, while the Ultra head effectively removes stubborn calluses and hard skin. Both work on dry and wet skin thanks to the rotating NanoTech surface with precision-textured design. Washable, rinsable and easy to replace.