Extrema Ratio specialise in military specification knives, conforming to military standards and precision manufacture. This level of expertise makes these new smaller scale knives virtually indestructible. The blades have an ambidextrous thumb stud and are made from N690 stainless steel which is rust resistant and holds an unbelievably sharp edge. The robust design incorporates a secondary locking mechanism which is very easily used and prevents accidental closing. It has a very secure pocket clip which wraps around the end of the handle.