Tungsten Carbide Blades put a quick sharp edge on dull or damaged knives. These carbide blades are precision ground on both ends so they are reversible and replaceable. Precision ground carbides provide a smoother, more consistent sharp cutting edge on your knife blade. They also sharpen your blade quicker than standard carbide blades. Replacement blades for: Smith's Edge Pro Pull-Thru Knife Sharpener (item # 50090) Two blades per set. See additional images for reference to the item that uses these particular carbide blades.