Question about be quiet! SilentWings 3 PWM High-Speed

I want to install these fans in the motorhome. The (absorber) fridge is grateful for a more intensive air exchange in summer. The control will then be via a part from AKASA, which is still pending. The cables are too short because I have to make the supply through cupboards. Are there extension cables for this at Digitec? I can find some on the net, for example from AKASA. Item no.: AK-CBFA01-30 EAN: 4710614530300 Do I have to order them from Conrad or do you have something like that? :-) MfG Werner Brülisauer