This knife is a practicable sheath knife. 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. Please look at the animation of the top page of this Web site. It is this type blade that we are cutting the bamboo in the bamboo grove. This blade functions most wonderfully if you wipe it without fail after use. The only one fault of YXR7 is rust easily.