PWM FAN SPLITTER CABLE connects up to 5 computer PWM fans to a single Molex 4pin header of your PSU and return RPM signal to computer by motherboard fan header; 1 to 5 fan converter cable connects an additional fan to increase airflow in your computer caseMolex 4pin plug connects to IDE 4pin on your PUS and splits the power to 5 PWM fans; Fans can spin at the same speed using software from a motherboard equipped with PWM controlMOBO 4-Pin receptacle connector to the 4-Pin header on motherboard that sends the RPM signal to the motherboard connector for synchronizing the fan speed with the other fan; 3 pin fan connector omits the RPM signal pin for tandem fan speeds with both fans3-PIN & 4-PIN FAN COMPATIBLE with popular brands of computer case cooling fans