Extra Coarse includes 100 extra coarse black sandpaper refills for your everyday needs.Thinning and Smoothing Feet The easiest way to get rid of calluses and old cracked foot skin, remove the rough sanded surface with stubborn dead skin, keratin and fine sandpaper to help refine and smooth feet.Easy to replace Grits pads are easily replaced to create a new double-sided file each time you use them, and the strong adhesive keeps the pads in place during use.The applicable thin file area makes it flexible to use in different areas of the foot and between the toes. Hygiene Ultimate quality, design and hygiene. Universal pedicure file refill.