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 pretensioning, a 22-position adjustment of the traction level and a 22-position adjustment of the pressure level, split between the high and low speed range (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, while on the 631/641 versions it is connected with a hose and can be fitted flexibly. The Classic version is the same as the "normal" version except that it has a black spring instead of a blue one. Approval: with operating licence (Germany only). As an option, the suspension struts can also be ordered at extra cost with hydraulic spring pretensioning (625). Wilbers products can be used for repairs and maintenance.