Unlike conventional 4-cylinder tail-lifts, the X4 Technology has two cylinders arranged one above the other in the lift or closing arm. On the one hand, this innovative arrangement means that the cylinders are better protected against possible collision damage and environmental influences, and on the other hand it means that more space is left for vehicle tail lights and trailer drawbar. The In Line design reduces bending and torsional forces so that material can be saved without loss of stability or performance, thus reducing dead weight.