This item includes 1 x 3 way fan splitter cable and 1 x 2 way fan splitter cable. One connects 3 computer case fans and one connects 2 computer case fans. The PWM splitter cables connects additional fans to increase airflow for you PC components whilst saving motherboard headers. The 4-Pin master fan header is wired to control fan speed and shares it with the other slave fans. The slave fans spin at the same speed as the master fan, using software from motherboard equipped with PWM control. These splitters are compatible with majority case fans on the market, such as the Noctua NF-P12, Corsair SP120, Arctic P12 case fans and many more. Add more cooling to your computer with this PWM fan splitter cable pack. Max power rating per fan: 12 watts; 4-pin or 3-pin fans compatible; Motherboard must supports 3 fans. The JBtek PWM Fan Splitter Cable Pack provides a quick and simple solution for controlling case fans in a computer case. Eliminate the need for separate fan control header on the motherboard. Now you can regulate the fan speed for 2 or 3 fans, with just one motherboard header, by connecting the 4-Pin RPM header to master fan, and 3-Pin slave header to the slave fans.