In extreme close quarters encounters where a suspect is attempting to take an officer's handgun, or an officer cannot access his handgun, the TDI knife is available as a "last option" knife. When worn on the pant belt the entire unit - knife and sheath - is well concealed. It also comes with a metal chain so it can be worn as a neck knife. Constructed from AUS 8A stainless steel with a serrated 2 5/16" blade and 5 5/8" overall.