12VDC fan 120 x 120 x 25 mm, 3-pin (positive, ground, tachometer) noise reduction

Fans for the cabinet ensure good cooling of the computer. This is especially important in newer computers due to a lot of heat generation.
Has a built-in tachometer, which gives a signal to the motherboard. Rotational speed can be controlled by voltage, so the noise must be reduced noticeably.