No.4 medium tank is a kind of medium tank produced by Nazi Germany in World War II. It was originally designed to support infantry and work with tank 3, which is specialized in anti tank missions. When the overall performance of No.3 tank gradually failed to meet the needs of armored combat in the middle of World War II, No.4 medium tank was transformed into main assault tank for armored division because of its mature technology and large room for improvement. During the Second World War, the No.4 medium-sized tank produced a variety of modified combat vehicles, including assault guns, self-propelled anti tank guns, ammunition delivery vehicles, bridging tanks and so on.