The versatile Boker Super Eraser is ideal for grinding, scouring, smoothing, cleaning and polishing metal surfaces. Especially with blades made of carbon steel, the typical dark stains and rust may appear over time. This is perfectly normal and is not a defect but may distort the appearance of the knife. To give the blades a new shine again, regular care with the Boker Super Eraser is recommended. Thanks to its 240 grit, the universal abrasive is perfect for grinding, scouring, smoothing, cleaning and polishing metal surfaces. Made in Germany.