Fallkniven FS4 Flipstone Sharpener – Dual Grit Ceramic & Diamond

The FS4 Flipstone is a compact folding sharpener built around a 3-inch tapered ceramic and diamond stone. The stone features a 1-micron ceramic side for fine finishing work and a 25-micron diamond side for coarser sharpening tasks. The smooth, flat surface makes edge work straightforward, and the design requires no oil or water to operate. The stone folds into a black Zytel handle that measures 4 3/8″ closed, allowing you to carry it like a pocket knife. A button lock holds the stone in place; depress it to flip the stone out for use or to fold it back for storage.