These special stones are designed for honing NIkasil plated cylinders found on some ATVs, motorcyles, snowmobiles, waverunners, and other small cylinders. Use with a Lisle 15000 or 16000 Hone to clean and hone the cylinders and produce a crosshatch pattern on the cylinder wall. The blended stone grit is less abrasive to protect the Nikasil cylinder wall. Each stone set includes 2 stones and 2 wipers.