What is it function?-Prepare the natural nail bed prior to any nail enhancement service What is different between Brown and Zebra?-A large barrel bit is helpful in shortening, shaping, and creating the perfect "C" curve-Zebra sanding help reduce heat and friction, keeps the filing dust from clogging, and extends the life of the nail file. This paper comes in a washable and non-washable version.-Cushioned nail files provide a better grip and ease of use, they also allow more control and faster refinement of the nail. What is the difference between Fine, Medium, and Coarse Grit?-Coarse nail grit are best for acrylic nail extensions-Medium nail grit are best to shape extensions of medium thickness, like most tips and wraps, and to shape the free edge of toenails-Fine nail grit are used for buffing and shining all types of nails. *Keep out of reach of children