RENNtech Adjustable Suspension HSM Kit for 212 - E Class / 218 - CLS Class 2014+ 4-MATICAs an upgraded option we offer our adjustable spring kit in combination with our RENNtech Hand Held Suspension Modul (HSM) in place of the rear adjustable links. This allows the suspension system to remain balanced as the digital lowering module controls inputs to all four sensors on the vehicle (even though only the rear suspension is adjustable electronically). It also allows for complete adjustability of rear ride height via the lowering module