Black blade ideal for applications requiring extra-sharpness. The OLFA UltraSharp black snap-off blades are exclusively designed for maximum cutting performance and are ideal for applications where superior sharpness is required. Made from high-quality Japanese grade carbon tool steel, the OLFA black blades are double-honed for extreme sharpness and are 25% sharper than the OLFA silver 9mm AB blades. Long lasting, durable snap-off blade - a new sharp edge with just a snap. Blade container locks for safety. Fits OLFA 9mm handles. 13 cutting edges per blade. 50 blades per pack. Olfa North America.