Usb Cabinet 80Mm Fan Quiet Cooling Fan System 4" With Speed Control, For, 2Pack The fans feature daisy connectors, and up to four identical fans can be connected, sharing the same governor and adapter. (When connecting, the switch of the first fan is the main switch, please adjust all other fan speed regulators to the H position, or other positions may cause the fan to fail to start.) Convenient USB Fan: The USB plug can be powered by a USB adapter or popular audio-visual electronic equipment and the USB port on the back of the game console to power the fan. Three-speed: The computer fan has a multi-speed controller that can set the fan speed to the best noise and airflow level. 3 gears, low (L), mid (M) and high (H), low-gear noise is only 21dB. High-end: Includes CNC machined aluminum frame with modern brushed black finish. High Quality: The double ball bearing features 65,000 hours long life with normal use, 7 blades generate strong airflow to keep the cabinet cool. DIY: The fan has a chrysanthemum connection port, and up to four identical fans can be connected to share the same one speed controller and adapter. (When connecting, the switch of the first fan is the main switch, please adjust all other fan speed regulators to the H position, or other positions may cause the fan to fail to start)