The Extrema Ratio Rao is not so much a knife as a feat of engineering. With the customary robust design and precision manufacture the Rao reaches heights of ingenuity never seen before in the arena of knife design. Purposefully crafted for the Folgore 185 RAO (Regiment Acquisition Objects) unit of the Italian Army it is required to perform in environments and over a period of time that most folding knives would not cope with.

The blade is made from N690 stainless steel with a testudo finish, tempered to 58/60 HRC. It is ingeniously double locked open or closed using a threaded hinge attached to the handle with an elastic lace and a slightly more conventional spring loaded, slide bar lock, making it one of the safest knives in the open position in the world. The grip of the handle is specially configured, anticorodal material whilst the extremely tough nylon sheath with leather interior, is designed to take the knife in the open or closed position. A diamond sharpener is also provided in the front pocket of the sheath which is compatable with MOLLE systems.