1、Made of high quality material, tough and durable. 2、Pen shape, mini size, portable and easy to carry. 3、Precision milled groove for sharpening fish hooks. 4、The flat surface on the back can be used to sharpen knives. 5、With a clip, can be fixed on the pocket. Features: Made of high quality material, tough and durable. Pen shape, mini size, portable and easy to carry. Precision milled groove for sharpening fish hooks.  The flat surface on the back can be used to sharpen knives. With a clip, can be fixed on the pocket. Suitable for outdoor knives, fishing hooks, etc.  Specification: Material: Diamond Color: Silver Optional Size: M, S M Length: Approx. 13.8cm / 5.4in S Length: Approx. 8.5cm / 3.3in Weight: Approx. 19-44g Package List: 1x Pen Shape Diamond File Using introduction: 1. Loosen the metal screw cap in anti-clockwise direction. 2. Pull the diamond rod out to the desired length and then securely retighten the metal screw. 3. Sharpen knife: Place knife in the flat section of the diamond rod and move back and forth until sharp. 4. Sharpen fishing hook: Place hook in groove and move back and forth until sharp. 5. Clean rod after each use with a dry cloth or dry soft tooth brush.