1. Excellent knife sharpener: our retractable diamond whetstone pen is very suitable for sharpening repair knives, serrated blades and scissors, large kitchen knives and smaller kitchen knives. There are some grooves on the semicircular surface that can be used to sharpen fishing hooks, needles, etc., so that the edge of the blade becomes sharp. 2. Small and : The pocket knife sharpener can be flipped and retracted. Then it can be adjusted to different lengths, shaped like a pen and equipped with a shirt pocket clip for easy storage. Very suitable for camping, outdoor adventure, hunting and fishing. 3. Sturdy material: the knife sharpener diamond is made of iron coated emery, which has excellent wear resistance, corrosion resistance, high temperature resistance, high strength and impact resistance. The grinding layer is fine and smooth, which can polish the knife well and extend the life of the knife. 4. EASY HANDLE: The Retractable Knife Sharpening Stone Pocket Knife Sharpening Stone is made of waterproof aluminum oxide, which is comfortable to grip and ergonomically designed. When you sharpen the tool, you will not feel fatigue or let the sharpening pen slip easily.