The WZ523 (sometimes also referred to as M-1984 by Western intelligence) was developed from the chassis of the Hanyang HY472 6X6 heavy-duty truck. An armoured personnel carrier (APC) variant of the WZ523 armed with a roof-mounted 12.7mm anti-aircraft machine gun (AAMG) was briefly demonstrated by the PLA during the 1984 parade in Beijing to celebrate the 35th anniversary of the People’s Republic of China (PRC). The WZ523 did not enter operational service with the PLA, possibly due to the PLA’s favour of the more capable WZ551 (ZSL92) 6X6 wheeled armoured vehicle introduced few years later.

In the early 1990s, NORINCO developed the ZFB91 (also known as Type 91 internal security armoured vehicle based on the WZ523. The vehicle features a weapon turret replacing the original roof-mounted 12.7mm AAMG. This variant has been deployed by the PLA Garrison Units stationed in Hong Kong and Macau. The main armament of the vehicle is a 35mm automatic grenade launcher, with 75 tear gas grenades. The secondary weapon is a 7.62mm machine gun with 1,500 rounds. If used in military missions, the machine gun can be replaced by a more powerful 12.7mm machine gun with 240 rounds. Other equipments include two 3-barrel smoke grenade launchers, a 300W search light, siren, and flash lights. The vehicle can be fitted with a bulldozer blade at front to remove obstacles.

The APC variant of the WZ523 for military was certified for design finalisation in 1993 under the designation ZSL93 (also known as Type 93). A number of variants were proposed, including armoured command vehicle, armoured ambulance, self-propelled mortar, HN-5C air-defence missile system, HJ-8 anti-tank guided missile carrier, and IR/laser reconnaissance vehicle, but none of these was produced.

The vehicle is 6.02m in length, 2.55m in width, 2.73m in height, and has a combat weight of 11.7 tonnes. The hull of the vehicle comprises three sections: the driver compartment in the front, the powerpack compartment in the middle left, and the troop compartment in the rear. Armour protection against 7.62mm calibre weapon systems is provided all round. The vehicle is fully amphibious, propelled by two water jets at the rear of the hull.

The WZ523 has a crew of two (commander and driver), and carries 10 passengers in its troop compartment. The vehicle is powered by a BF6L913C-Q 6-cylinder, air-cooled diesel that produces 165hp, and has a maximum road speed of 85km/h. 80% of the parts on the WZ523 chassis are exchangeable with the standard HY472 truck.