A full sharpening kit that fits in a shirt pocket. The Marttiini Diamond Sharpener Pen packs a 300-grit diamond-coated rod, a hook sharpening groove, and a flat sharpening surface into a compact pen-sized tool that stores inside its own barrel when not in use. A pocket clip keeps it accessible wherever the work is happening.

The diamond rod handles kitchen knives, filleting knives, ice augers, and skinning knives — the same diamond coating that makes the full-size sharpening steel effective, scaled down for field carry. The hook groove is a practical addition for anglers who want to touch up fishing hooks on the water without carrying a separate tool. The flat section of the sharpener works as a first-aid edge treatment for blades that need more than a quick honing pass.

Use with water for best results, then wash and dry after each use. When sharpening, keep the tool stationary and move the blade along its surface rather than the other way around.

• Brand: Marttiini
• Country: Designed in Finland, Made in Estonia
• Sharpener Material: Steel Alloy / Diamond Granulation
• Length of Sharpener: 3.14" (8 cm)
• Total Length: 7.87" (20 cm)