Older fans often have no PWM control, and certainly no temperature-dependent speed control. Such fans can then usually be tethered only via a fan controller, which controls the voltage applied to the fan via a potentiometer. However, if a controller is too expensive, or if you only want to downgrade one or two fans due to increased noise, you can do without a controller, as it can usually control three or more fans. Why, if you only have two and a third and fourth are not needed, or not at all fit into the housing? This 3-pin power adapter from Akasa solves this problem in the simplest way. Simply plug in between power supply / motherboard and fan and in one fell swoop the fan instead of 12 volts only 10 volts, so about 20% less voltage, which leads to a reduction in speed and thus a reduction in volume. Heavenly peace at an unbeatable price! Technical details:Voltage reduction from 12 to 10 volts, approx. 20%Connection: 3-pin