BMP-1

The BMP-1 is a Soviet amphibious tracked infantry fighting vehicle. BMP stands for Boyevaya Mashina Pekhoty 1 (Russian: Боевая Машина Пехоты 1; БМП-1), meaning "infantry fighting vehicle". The BMP-1 was the first mass-produced infantry fighting vehicle (IFV) of USSR. It was called the M-1967, BMP and BMP-76PB by NATO before its correct designation was known.
The Soviet military leadership saw any future wars as being conducted with nuclear, chemical and biological weapons and a new design, like the BMP, combining the properties of an armored personnel carrier (APC) and a light tank would allow infantry to operate from the relative safety of its armoured, radiation-shielded interior in contaminated areas and to fight alongside it in uncontaminated areas. It would increase infantry squad mobility, provide fire support to them, and also be able to fight alongside main battle tanks.
The BMP-1 was first tested in combat in the 1973 Yom Kippur War, where it was used by Egyptian and Syrian forces. Based on lessons learned from this conflict, and early experiences in the Soviet War in Afghanistan, a version with improved fighting qualities was developed, called the BMP-2. It was accepted into service in August 1980.
In 1987, the BMP-3, a radically redesigned vehicle with a completely new weapon system, entered service in limited numbers with the Soviet Army.
https://en.wikipedia.org/wiki/BMP-1

Shown with "Sagger" anti-tank missile mounted on the main gun.