Diamond drill bit suitable for natural nails as well as artificial nails, great tool for any professional manicurist or beginner Used in hardware manicure and pedicure: Cleaning up nail cuticles Smoothing and shaping gel or acrylic nails Helps manicure to last longer Diameter of the working part, mm: 3.10 Shank diameter: 2.35mm (3/32”) fits for most electric manicure machine on the market Grain size: small (red)