1.Package include: you will receive 4 x curved foot file which can be shared with your family and friends 2.Double-sided sanding: the exterior is made of fine sand surface, and the interior is made of coarse sand surface; Different levels of sand surface can handle the problem of the feet more flexibly 3.Groove design: internal concave design for better fit to the heel and feet edges, and external design for the sole of the foot; Considerate design to take care of every detail of the foot 4.Good material: made from ABS plastic, the u shaped curved foot file is not only light but also durable for its hard structure so it has long lifespan that can serve you for a long time 5.Convenient and practical: your feet can be treated at home to avoid the pedicure of the salon, and the old man will have smooth heel, look younger and walk more comfortable