Optimised response characteristics and large reserves create very good road adhesion for great grip and high comfort. These suspension struts with reservoirs permit infinite adjustment of the spring pre-tensioning, a 22-position adjustment of the traction level and a 22-position adjustment of the pressure level, split between the high and low speed ranges (short surface irregularities/long strut movements e.g. on traffic bumps). The reservoir with pressure level adjustment is located directly on the suspension strut on the 632/642 and 633/643 versions, on the 631/641 it is connected with a hose and can be fitted flexibly. The classic version complies with what is "normal" but has a black spring instead of a blue one. Approval: ABE operating licence (Germany only). As an option, the suspension struts can be ordered at extra cost with height adjustment (629) and/or hydraulic spring pre-tensioning by means of a handwheel (625). Wilbers products can be used for repairs and maintenance.