Extrema Ratio Misericordia DesertExtrema Ratio Misericordia Desert The Extrema Ratio Misericordia, adopted by the 4th Alpine Ranger that helped develop and test the product. It is a tactical fixed blade knife, extremely light and compact, it can be used both as a main knife or as a backup blade. The blade of the new Extrema Ratio Misericordia is milled out of Bhler N690 steel, hardened at 58 HRC, it is 118 mm 4. 64 long and 4mm 0,16 thick and plain edged. The blade has a spear point