1.Each double-sided nail file is composed of sandpaper and EVA. It is healthy and can quickly and easily polish your nails to the shape and size you want. 2.Double-sided emery board, soft nails or hard nails can be used, relatively thick, durable, not easy to break or damage, one can be reused for a long time. 3.These nail files are suitable for fingernails, toenails, natural nails and fake nails, suitable for professional manicurists or beginners in nail art, and also suitable for girls who like nail design. 4.Safe materials are non-toxic and harmless, have no allergic ingredients, will not cause damage to your nails, are skin-friendly and safe to use. 5.Mini nail files are small in size and light in weight, easy to carry and store, and can be carried in a bag without taking up too much space.