BT-7 fast tank
The BT-7 was the last of the BT series of Soviet cavalry tanks that were produced in large numbers between 1935 and 1940 (BT relating to Bystrokhodny tank - fast/high speed tank). They were lightly armoured, but reasonably well-armed for their time, and had much better mobility than other contemporary tank designs, based as they were on the American-designed Christie suspension and thus achieved impressive speeds of up to 53mph.
In June 1941, at the outset of the German invasion of the Soviet Union, the BT-7 was the main battle tank of the Soviet army. Tank losses were high, with over 2,000 BT-7 series tanks lost in the first 12 months on the Eastern Front. Hundreds more had been immobilized before the invasion by poor maintenance, and these had to be abandoned as the Soviet forces withdrew eastward. Still, the BT-7 continued to be produced, and was used by the Russians in the east, where Japanese forces lacked the heavy tanks of their German allies.