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: 1.4 Shank diameter: 2.35mm (3/32”) fits for most electric manicure machine on the market Grain size: medium (blue)