This is the sharpest, strongest, replacement razor-blade 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 surgeon's scalpel. The 3.5" Japanese 420J2 stainless razor-blades are precisely heat treated and hand finished shaving-sharp. The double molded Grivory handle features rubberized TPR inserts for a non-slip grip, even when wet.