Stages 1 and 2 use 100% diamond abrasive disks Stage 3 uses ultra-fine, proprietary stropping disks. Produces patented triple bevel Trizor-Plus™ edge on all commercial kitchen knives and sport knives. Sharpens straight-edge and serrated knives. Sharpening module is commercial dishwasher safe. Recommended for larger commercial kitchens as replacement for outside sharpening services. 12 x 12 x 31cm high.