The WZ 501 (YW 501) or Type 86 is a tracked armoured infantry fighting vehicle designed and manufactured by the Chinese Defense Company Norinco. The WZ 501 is based on the Russian-made BMP-1 armoured infantry fighting vehicle, the only major differences being slight reductions in weight and maximum road speed. The WZ 501 was seen for the first time during a military parade in Beijing late in 1999. It was estimated that the PLA maintains roughly 1,000 examples of the Type 86 IFV in operation. Most of these vehicles are deployed by armour units stationed in Northern China. The PLA Marine Corps in the southern Guangdong Province is also equipped with the amphibious variant Type 86B. The WZS 501 was also exported to Myanmar, Iran, Iraq and Sri Lanka.