CARBIDE (Coarse) * Removes metal quickly to reshape a dull edge (44? inclusive angle/22? per side). CARBIDE (Medium) * Further refines the edge, less abrasive than carbide. CERAMIC (Fine) * For finishing the edge and fine-tuning knives after each use. The perfect, pocket-sized sharpener for shaping and maintaining a razor-sharp edge on all your outdoor and kitchen knives. The pivoting X-base folds out to improve safety and stability during sharpening for a more precise edge. Set at a universal 22 degree angle, the coarse tungsten carbide bits reshape a dull blade quickly, while the fine ceramic rods finish the blade to a razor*s edge. The rubberized TPR finger hold ensures a non-slip grip and four 3M rubber foot pads secure the X-base to most any flat surface. After use, the Sharp-X folds down flat for storage.