The Ural-375 is a general purpose 4.5 ton 6×6 truck, produced at the Ural Automotive Plant in the Russian SFSR since 1961. The ZIL-157 was the standard Soviet truck until it was replaced by the Ural-375D, which became the standard Soviet truck in 1979. The Ural-375D was soon replaced by the Ural-4320.
The Soviets found the trucks an ideal platform for the BM-21 Grad rocket launcher. Other modes for the Ural-375D included troop carrier, supply carrier, etc.
Additional Information: en.wikipedia.org/wiki/Ural-375