[Trak Ratt]

If you go to the Bilstein tech site and others they explain it a lot better. But Non technical explanation, Bilsteins and some others can be dismantled and rebuilt using different size internal orifices and disks (valves). These control the flow of oil inside the shock and therefore the piston(s) movement. “Gas” shocks use a pressurized gas (hydrogen?) to limit oil frothing as the piston moves up and down, remote reservoirs provide more oil volume to help cooling. Way simplified, maybe Matt can chime in?

Steve you need to think about changing your subscript after last weekend Something like engine in – car on track