The Cold Steel Knife Mini Koga SD2 91MK is a self-defense tool which is manufactured by the company Cold Steel. The weight of the tool is 2.1 OZ and the overall length is 61/2 inches. The thickness is one inch and the size is such that it perfectly fits in the hand of the user. It is best used for the training purposes and is used as a glass breaker. Made of polymer, is durable and lightweight as well. The end of the tool is pointed and has an ergonomic construction which helps the one to use it with perfection.