The Own Harmony Callus Sander is perfect for frequent use or last-minute touch-ups so you can always be your best self for every occasion. The convex-curved rollers have 11% more surface area than pumice stone, metal files, and grater-like tools. It's easy to clean and use, splash-proof for quick rinsing. You'Ll look forward to it, minus the cost of a pedicure spa, at least for 45 mins continuous use. - Own Harmony is a USA Certified Woman Owned Small Business. Our vision is to make the foot and personal care experience easy, effective, and enjoyable. Customer experience is at the core of everything we do. Our package includes 110 - 240V Dual Voltage Worldwide Charger & 2 extra mineral rollers: 1 Regular and 1 Coarse. Protective Cover, Cleaning Brush, User Manual, and Support Card As Easy as 1-2-3. How to Use Your New Electric Callus Remover for Best Results: the CR900 Electric Callus Remover is available in a range of sizes. It comes with 6 rollers - 2 nail buffing, 2 polishing, and 2 callus remover (Regular & Extra Coarse).