The intelligent programmed temperature controller & accurate temperature detection make ARCTIC F Pro TC the best TC fans in the market. Unlike other generic temperature controlled case fans the ARCTIC F Pro TC fan provides cooling according to not only the temperature but also the overall necessity for cooling. The revolutionary programmed temperature controller plays a key role. As shown in the chart when case ambient air temperature is at safe level 0°C to 32°C the ARCTIC F Pro TC fan speed remains at its lowest (500 rpm). This is to offer adequate ventilation at the lowest noise level possible. The ARCTIC F Pro TC is therefore completely inaudible (0.05 sone) at low temperatures a much quieter level than generic TC fans.