Fällkniven Flipstone FS4 Folding Sharpening StoneThe Fllkniven Flipstone FS4 is a compact, dual sided sharpening tool designed for those who demand razor sharp precision anywhere they go. Resembling the size and shape of a pocket knife, this innovative flip style sharpener easily fits in your backpack, tackle box, or pocket, making it ideal for outdoor enthusiasts, hunters, and everyday carry users alike. Featuring two high performance surfaces, the yellow side uses a diamond abrasive (25 microns)