These are diamond impregnated double sided wheel for sharpening TIG Welder Tungsten Electrodes. Get 100 sharpening’s on each side for a total of 200 sharpenings per wheel. These wheels fit the TG1800 (33307) and the original Eastwood TIG Welder Tungsten Grinder (21526). Diamond impregnated double sided wheel for sharpening Tungsten Electrodes Get 100 sharpening’s on each side for a total of 200 sharpenings per wheel These wheels fit the TG1800 (33307) and the original Eastwood TIG Welder Tungsten Grinder (21526) Use these as a back-up for TIG Welding jobs so you do not run out Eastwood Offers 100% Satisfaction and Lifetime Technical Support Specifications 1" Diameter Double Sided Abrasive Maximum RPM: 40,000 Rated for over 100 sharpenings per side