This hook sharpener is a convenient sharpening system that features a diamond grit sharpening rod. The fine grit rod folds into lightweight plastic handles for easy carrying. The diamond grit will sharpen your hardest hooks and the different size sharpening grooves will sharpen hooks up to size 14/O. It was designed with fish hooks in mind but the fine diamond grit will also work great on knife or tool edges in a pinch. The Lansky Diamond Fish Hook Sharpener is an essential item for any tackle box!