For connecting a fan with a 3-pin Molex connector (CPU cooler, case fan, etc.) to a power supply plug (4-pin). The adapter allows the fan to operate at 7 volts instead of 12 volts, which leads to a reduction in noise. Please note, the fan's speed and accordingly the airflow will be reduced. Important: Please note that it can come to damage by older power supplies without overload protection, if the adapter is loaded with more than 500mA.