Lansky LFRDF Folding Diamond Rod. This versatile 3.5" folding rod sharpener is great for proper knife maintenance, including sharpening of straight-edged blades, some scalloped blades, and even gut hooks. The sharpening rod features a fine diamond grit and it stores in the comfort-grip, non-slip handles. The perfect sportsman sharpening hone for hunters, backpackers and fisherman.