This is an adaptor which has a 3-Pin fan connector and a 4-Pin PWM fan connector. It can be used to connect a PWM fan to a fan controller or Mainboard. This signal does not pass on a rpm signal, but most fan controllers can adjust the speed of the fan via the voltage. This cable is not only practical, it is also optically appealing, The surrounding mesh, also called sleeve, which is surrounding the cable itself offers the advantages that every Pro-modder is looking for: A completely unique look, even of the cables in the system! Special attention was paid to the combination of cable connectors, sleeve and heatshrink which were used to ensure great design and a unique as well as elegant look. Phobya's goal is to make the work of professional and hobby modders a bit easier with these cables. Sleeving is a lot of work and requires much time. But with these cables by Phobya the whole system can be redesigned any way you like by simply adding these cables.