This is the sharpest, strongest, replacement razor-knife available, with blades that change safely and easily at the push of a button. The black-oxide coated blade holder supports the razor-blade for the strength of a standard knife and sharpness of a surgeons scalpel. The 3.5" Japanese 420J2 stainless razor-blades are precisely heat treated and hand finished shaving-sharp. Rubberized TPR handles are mounted to sturdy stainless steel liners for unparalleled strength, and a non-slip grip even when wet. Comes complete with six replacement blades.