The 9000-23 is the original equipment replacement 1 inch wide grinding wheel for both the MAG-9000 and MAG-8000. We recommend this wheel as the most productive. It removes the most steel in the least amount of time. If you are most concerned about decreasing sharpening time, this is the wheel for you. It is the most highly recommended wheel for all Magna-Matic sharpeners for its extreme productivity, and labor time savings. Note about ordering grinding wheels: Shipping charges are almost the same cost for 1 - 3 wheels, while we have NO minimum order, you are best off to at very least get 2 or 3 wheels as a lowest quantity for the shipping cost.