Inert 20mm Swiss target practice tracer round used in the Oerlikon 20mm 5TG cannon. This 20x128mm casing is made of steel and is in good condition. The Oerlikon 20mm 5TG, presently known as the KAB, was developed by Oerlikon after the close of hostilities of WWII. It has a gas-operated mechanism to unlock the breech. It was the first Oerlikon gun design that differed radically from the original Becker design.