This knife sharpener provides results that are close to a professional knife sharpening service. The Edlund 401 is NSF Certified and has a pop-out, easy to clean & replaceable knife guidance system. It has a precision guidance system to maintain a perfect edge, and an ABS plastic knife guide for easier cleaning and ease of operation. Knife guide allows knife heel to be inserted closer to stone to maximize sharpening area. Sharpens knives from 3⁄16" to cleaver blades. Grinding wheel assembly is replaceable. NSF Certified.