The R 439 full-tracked APC has been developed as a private venture by Rheinmetall Landsysteme (previously known as Thyssen Henschel) to transport men and equipment over marginal terrain especially swamp, sand, mud and snow.

It is basically the German Kassbohrer Flexmobile FM 23.150K all-terrain chassis, already produced for a number of civilian applications. Fitted with a fully armoured body, it provides its occupants with protection from 7.62 mm small arms fire and shell splinters. A higher level of ballistic protection can be provided by using compound armour.

By 2001, volume production of the R 439 had yet to commence. This vehicle was originally referred to as the TH 439 then the H 439, but as it is now part of Rheinmetall Group it is now called the R 439.

The diesel engine is at the front of the vehicle with the personnel compartment to the rear. The commander and driver are seated at the front of the vehicle with a large bulletproof window to their front. When required, these can be covered by a shutter hinged at the top. A forward-opening door is provided in each side of the hull and in its upper part is a bulletproof window.

In either side of the rear troop compartment are two bulletproof windows and in the hull rear is a door that opens to the right with a window above. The troop compartment is provided with seats, extractor fans and a heater.

The vehicle uses rubber tracks that can be fitted with bolt-on double steel web plates for difficult terrain; one width of summer track and two widths of winter track, all steel, are available. The main roadwheels use a double-track guided system and are self-cleaning. Either side of the vehicle are five dual roadwheels with drive sprocket at the front, idler at the rear and three track-return rollers.

The interior and interchangeable lateral wall and roof segments enable the R 439 to undertake a wide range of roles including APC, weapons carrier, ambulance, command post vehicle, tractor and specialised reconnaissance vehicle.

Options include a KHD air-cooled diesel engine developing 152 hp in place of the Mercedes-Benz OM 352A diesel engine, hatches for crew in the rear part of the roofing, firing ports with vision blocks within the sidewalls and rear door and a hatch for a 7.62 mm machine gun above the commander's seat.