From the product description, this device basically aids in silencing your noisy fans when the system does not need it. For example, if you are heavily using the system, more than likely CPU temperatures will rise which will also raise case temperatures. This rise in turn causes the sensor on the Pyramid to kick in and start the process of pumping more juice to the fan. As soon as case temperatures drop, the sensor sees the change in temperature and starts limited the amount of voltage, causing whatever fan that's attached to slow down. This minimizes noise when it is not needed without much human intervention.