This knife is one of Rockstead's flagship sheath knives. The shape of the blade is dual convex. The technologically advanced process and materials used in the production of this blade, prohibits others from creating anything similar and we have confidece in our blades surface. When pushed with force, this knife will cut through a phone book as if it were butter. Please confirm the improved sharpness of our evolved dual convex blade. ZDP189 is a powder stainless steel developed through the use of nanotechnology specifically for cutting implemets. However, this knfe is not well suited to chopping.