The primary advantage of the BRDM-1 at the time of its introduction was its amphibious capability, which was the main shortcoming associated with its BTR-40 counterpart. Another unique feature of the vehicle's design were two pairs of chain-driven auxiliary wheels, which could be lowered to provide additional traction on muddy terrain. The BRDM-1 was manufactured from 1957 to 1966, at which time 10,000 had entered service with the Soviet Union and its military allies around the world. It was thereafter superseded by the improved BRDM-2, which possessed greater amphibious capabilities, a more powerful engine, and a fully enclosed turret.