The Coboc TX4SPL2-12 splitter cable allows you to connect two PWM fans to a single pin header on your motherboard. Only one of the male connectors has the full 4-pin structure for complete PWM function. And the cable is fully sleeved, making for a clean, professional look inside your chassis.

-
Compatible with 4-pin PMW fan connector and 3-pin fan connector
-
Only one of the two fans sends its tach signal (the one with full 4-pin connector) and reports its RPM, but the other one will still follow the PWM signal.
-
The other connector's tachometric signal pin is missing, which ensures your fan speed monitor won't bounce all over the place from getting two sense signals. This guarantees your motherboard gets an accurate RPM signal.