These blades fit all of AccuSharp's products except ShearSharp(R). For the best possible sharpening edge, they only use the finest American-made diamond honed tungsten carbide available. The result is the finest line of carbide sharpeners on the market today, at any price. These blades are reversible for double life and most users report an average life of 5 to 10 years between replacements. Beware of other brands that use cheap imported carbide! Insist on AccuSharp(R).