Wolff Industries Coarse Wheel for Twice As Sharp Made in the USA It is especially useful when

It is especially useful when sharpening large knives or many knives in succession

This type of file takes less pressure to remove desired amount of metal and does not wear or load as rapidly as a double cut file

The Wolff 600 Grit Diamond Wheel is for those times when you want a wheel that will remove more metal than the 800 Grit Diamond Wheel (used for for fine shears) but not as much as the 400 Grit Diamond Wheel (used for general purpose scissors)

it helps keep knives sharp but it does it by steeling

Wolff Industries Coarse Wheel for Twice As Sharp Made in the USA It is especially useful when46 Grit for Heavy Material Removal The Wolff 46 Grit Silicon Carbide Wheel is an optional wheel for the Twice As Sharp Scissors sharpener. It is ideal for fast material removal on heavy steel blades like lawn mower blades. This wheel has an arbor hole of 1" diameter. It comes with bushings for 7 8", 3 4", 5 8" and 1 2". It can be used on any of the Twice As Sharp sharpeners. Wolff Industries Part #27146