The Extrema Ratio Survival Kit A.M.F. uses high-quality Austrian Böhler N690 cobalt stainless steel for its blade, which has a hardness of 58 HRC. The blade is coated with a MIL-C-13924 bluing finish, providing excellent corrosion protection and minimizing light reflections. Furthermore, the knife is designed for easy disassembly for maintenance or thorough cleaning.