The Olfa Extra Heavy-Duty Utility Knife features a large, fiberglass-reinforced handle with a non-slip cushion grip for secure handling. A ratchet-wheel lock blade slider allows for unlimited blade position and custom cutting depths. The blade is made from high-quality, Japanese carbon tool steel. These blades are durable, long lasting and 25% sharper than standard Olfa silver blades. The knife comes pre-loaded with one 25mm Heavy-Duty Extra-Sharp black blade.