The Y-Splitter allows you to connect 2 fans to one fan header.
4-Pin y-splitter
The Y-Splitter allows you to connect 2 fans to one fan header.
Phanteks PH-CB-Y4P, 4-pin PWM, 2 x 4-pin PWM, Female, Female, Straight, Straight
Phanteks PH-CB-Y4P. Connector 1: 4-pin PWM, Connector 2: 2 x 4-pin PWM, Connector 1 gender: Female