In Brazil we have an urban combat team, "BOPE" (Special Operations Battalion), considered one of the best in the world. Here they are called "Skulls", because wherever they go they leave their trail of death, (remembering that most of the fights are carried out inside favelas in Rio de Janeiro, with highly dangerous drug dealers, so nothing more fair).
Training course lasting 4 months, only for Police officers, where only 1/3 of those enrolled manage to graduate.
Having said this summary, I present to you an exclusive knife for BOPE students, however the person enrolled in the course did not graduate and the knife ended up in my hands.
Built by renowned Brazilian knifemaker Ricardo Villar.