They are Nivomat Shocks and yes they will support wieght and add lift.
Here's some info about them.
Nivomat maintains a level suspension, front and rear, while trailering or at a fully loaded condition," says Uwe Grasse, product engineering manager.
Nivomat is a semi-supporting system working in combination with a mechanical spring. The Nivomat shocks are only mounted on the rear where most of the additional weight is located.
Nivomat looks like a standard shock absorber with a piston rod with damping valves at the end, an outer tube and a cylinder tube. Several components are added to provide the leveling function. Two reservoirs are contained in the outer tube, an oil reservoir (or low pressure reservoir) and a high pressure chamber. Inside the piston rod is the pump chamber (with inlet and outlet valve) and the pump rod, which serves as a height sensor or regulator and a release bore which releases the pressure after the vehicle has reached level.
A load initially causes static compression of the vehicle's suspension. Once the vehicle begins to move, the pump is activated by the relative movement of the body. Extension of the piston rod causes oil to be drawn through the inlet valve into the pump. Compression then pushes the oil through the outlet valve into the high pressure chamber. The pressure in the oil reservoir decreases as the pressure in the high pressure chamber increases. The increasing pressure acts on the piston rod and raises the vehicle at a continuous rate.
Once the vehicle has reached optimum height, oil is no longer drawn in. The height regulator opens a bypass between the high pressure chamber and the pump chamber preventing oil from flowing out of the oil reservoir.
When the vehicle is unloaded the vehicle begins to rise. The height regulator opens the release bore. Oil flows out of the high pressure chamber into the oil reservoir, the pressure drops in the high pressure chamber and the vehicle lowers to the initial height.
Since Nivomat is mechanical, the vehicle needs to be moving before the pump starts to work and it takes about a mile to a mile-and-a-half of travel before the vehicle reaches its optimal level point.
"It takes very little input to actuate the pump," says Hunt, "about plus or minus a millimeter is all it needs, so even on smooth roads the Nivomat pumps up quite quickly."
But the Nivomat system doesn't just level the vehicle under load. As the load increases, the pressure inside the shock increases as oil is displaced from the reservoir to the inside of the unit, compressing the gas volume. This creates a progressive increase in spring rate and damping with little or no change to ride frequency.
"At a high GVW or max load, the ride frequency would be almost the same as curb position, but would never go as low as a conventional suspension," says Grasse.
"Rear air leveling is the direct competitor to this product," says Hunt. "But with either a conventional suspension or air-leveling suspension you don't get a significant increase in spring rate with load like you do with Nivomat."
He also points out that a standard air compression system is made up of 14 parts, many exposed to the environment, adding some 30 pounds to the vehicle. The Nivomat system has only two parts weighing half as much, which reduces assembly plant inventory and logistics problems.
