Light wheel-track tank BT-5 was created as a result of modernization and improvement of combat and technical characteristics of the tank BT-2. The main difference of BT-5 became a new turret with more powerful arms: a 45mm cannon 20-K. An engine 'Liberty' was also changed for a native M-5 (than it was M-17), was enlarged a size of fuel and lubricant cisterns, was improved transmission construction and some elements of tracks. The tank BT-2 fought in Spain in 1937-38, on the lake of 'Khasan' in 1938, in Mongolia, in Finland in 1939-40 and also during the World War II in 1941-1945.There were manufactured more than 2000 samples of the tank BT-2 and its modifications.