Supports up to 4 Independent Fans FH-04 enables users to greatly expand cooling capability within the chassis and enjoy enhanced system performance. FH-04 is able to extend up to 4 fans and compatible with 3-pin/4-pin Fans. PWM Function Design Each port has its own PWM function and the fan speed can be adjusted at the same time, but only the speed of Fan 1 can be identified by the system. Easy to install FH-04 is easily installed by included double-sided adhesive.