Abrasive stone

Crystolon (silicon carbide) combination benchstones have both coarse and fine grit silicon carbide surfaces.These fast-cutting stones sharpen edges on your tools to moderate tolerances quickly. Dark gray in color.

India (aluminum oxide) combination benchstones have both coarse and fine grit aluminum oxide abrasive surfaces and will produce strong, keen, long-lasting edges on quality tools. Orange/brown in color.

These are Carborundum GOOD tier products.

Features & Benefits
Crystolon
Sharp, silicon carbide abrasive
Enhanced cutting action
Fast stock removal
Vitrified vond for long life and excellent form holding

India
Aluminum oxide abrasive
Fast, cool cutting action
Maintains high part tolerance
Vitrified vond for long life and excellent form holding

Options : ceramic fiber, silicon carbide, ceramic