This is a proven professional knife sharpening system that has been proven to work all over th world. The Tru-Hone name is unsurpassed in the word of high volume knife sharpening. By removing as little metal as possible, the Tru Hone extends the life of your knife while quickly and efficiently raising and refining an incredibly sharp edge. The patented wheel design allows two overlapping wheels to rotate upwards into the edge of the knife blade. Variable speed is available if overheating is a concern on a badly damaged knife blade. The difference between the light commercial machines and the heavy machines are: Larger Bearings HCA has ALL ½" Gears LC has ¼" & ½" Gears Two Drive Belts Connecting the Motor & Gear Train Heavier Duty Speed Control with Micro Switch The 1500 grit polishing conversion kit includes: 1 Set of HW1000 Honing Wheels 2 TH1812 Wide Brass Washers 1 TH1242 Honing Wheel Cover 1 TH1716 Sponge 1 CLD2 Cleaner 2 oz. 1 Water Bottle We are authorized distributors for Tru Hone. All machines and parts come with the EXACT warranty that you will get through the manufacturer directly. Both knife sharpening machines have a 12 month service guarantee on all parts and labor except the honing wheels and drive belt. Texas Sharpening provides an additional 30 day satisfaction guarantee. You can return the machines at no cost to you if you are not 100% satisfied.