The Diamond Retractable Sharpener features a diamond-coated steel rod designed to sharpen straight and serrated blades with precision. Multiple layers of medium-grit monocrystalline diamonds provide efficient material removal while maintaining a refined edge. The reversible rod offers a tapered surface for serrations and a half-round surface for straight edges, and it adjusts to variable lengths for convenience. A built-in groove accommodates hook sharpening, while the compact, pen-sized design with pocket clip allows easy carry and storage. The rod retracts into the handle when not in use for added protection.