Auxiliary apparatus for patients for connecting tubes and pipes; dialyzers; accessories for dialyzers; connectors and connecting systems for medical apparatus, instruments and for medical purposes, in particular for catheter caps; connectors and connecting systems for tubular and pipe-shaped connectors for medical purposes; connectors and connecting systems for Luer systems, for medical purposes; equipment and apparatus for replacing catheter caps; adapters for closure systems for medical purposes, in particular for Luer systems for medical purposes; and accessories and spare parts for the aforesaid goods; all the aforesaid goods exclusively relating to dialyzers