Hand protection is KEY to keeping your hands from ripping and ruining your momentum. But hand MAINTENANCE is just as important. That's why JerkFit has teamed up with SandBar® to offer this premium callus sander and maintenance kit! The SandBar® is the Ultimate Callus Management System More effective than a pumice stone or file No parts/components to replace Safer than razor blades, scissors or pocket knife More durable than competing products Created, tested and approved by elite athletes Proudly assembled in the USA One year warranty, satisfaction guarantee! Each hand callus remover kit comes with a SandBar ®, BarButter ™, our 100% all-natural salve formulated specifically for dry and damaged hands, and a reusable protective tube PLUS a new silicone scubber to clean the SandBar with.