Synthetic grinding wheels are produced through a manufacturing process developed specifically for sharpening ski edges, with excellent results. There are six grinding wheels, with different grits: 80/120/240/320/500 and 46. /80 (BLACK): developed for setting the angle with our Carrot system. /120 (RED): developed for maintaining the angle, suitable for compact winter snow and recommended for the Baby/Cuccioli/Ragazzi/Allievi categories. /240 (YELLOW): this grinding wheel leaves a less aggressive edge than the 120, while allowing you to achieve more precise turn initiation. /320 (BLUE): this grinding wheel was developed to meet the demands of speed disciplines. It leaves a slightly aggressive edge that glides very smoothly over the snow surface, while still providing an immediate response when the ski is put on edge. This feature is very important because athletes need confidence at high speeds. /500 (GREEN): the 500-grit grinding wheel has many of the characteristics of the 320, but with one difference: it leaves an even cleaner edge, making it particularly suitable for courses with little gradient, where glide is especially important.