Shapton NAORU Cast Iron Lapping SystemHighlights Synergy of geometrical grooves with lapping powders Improves speed and accuracy in flattening sharpening stones Includes medium and coarse grit lapping powders Description The Shapton NAORU Cast Iron Lapping System is a powerful tool for restoring the original capabilities of your sharpening stones. Its surface is covered with grooves laid out in a geometrical pattern based on the principles of physics. These grooves increase the synergy