The primary components include a coupled piston and a direct current motor located in the hollow piston rod. This motor actuates two rotary disks situated in the piston rod, which are both equipped with individual piston valves. This way, two independent characteristics can be realized as in the figure. In order to make the adjustment effective both in the rebound and compression directions, a spring loaded check valve is assigned to each rotary valve for the rebound stage and a soft one for the compression stage.