The HFX® Safety Control system prevents the Classic or Mini Metal from overheating by adding a 92mm safety fan (mCubed-X92) and a single channel fan controller. The fan only rotates when it reaches a given temperature. You can adjust the activation temperature by rotating the right knob on the amplifier. When the FanAmp light illuminates the fan is running at 100%. If the temperature falls under the given temperature, the speed will be reduced (built-in delay/ Hysteresis). The fan attaches to the roof of the Classic or Mini Metal case and is designed to extract the warm air out of the case rather than blow air into the chassis.