This knife is a flagship of the sheath knife of ROCKSTEAD. The shape of our blade is made from a consecutive convex surface. This is a technology that doesn't permit other follows, and we have confidence in this surface. When you strongly press this knife against the telephone book, it will cut like cutting butter. Please confirm our HONZUKURI blades that evolved. The handle of UN can be detached. We are developing new practicable handle attachable to this knife. ZDP189 is a powder stainless steel material developed for cutlery. It is a product of the nano tech. Sharpness did not decrease so much to the blade of ZDP189 after having cut hard Manila rope 780 times. However, it is an unsuitable knife to the beating cut. This knife is three-quater tang. Please choose the color of the silk cord of the handle freely from among 4 colors. (KINCYA,UGUISU,TETSUKON and AZUKI)