Power D-type Interface
Four interfaces, three voltages.
Different voltages with different airflow, speed, and noise.
You can select the appropriate voltage interface to start the fan.
5V interface: (1500RPM) Small airflow, very quiet.
7V interface: (2000RPM) Moderate airflow, relatively quiet.
12V interface: (3000RPM) The fan working at full speed, big airflow.