A ballistic knife is a Specialised combat knife with a detachable, self-propelled blade that can be ejected to a distance of several meters by pressing a trigger or operating a lever or switch on the handle. Ballistic or &quot;firing knives&quot; are believed to have first appeared as part of the equipment issued to Soviet and Eastern Bloc special forces formations, such as the Soviet Voyska Spetsialnogo Naznacheniya, or &quot;Spetsnaz&quot;.