With the Silent Fan Series, yiu get a revised fan blade design, the use of extremely durable Rifle-bearings are the outstanding features of this silent fan series. The Cooltek Silent fans are ideal for budget conscious users who are not willing to make compromises in quality. This model has a 4-pin PWM connector for automatic speed control. Over a 4-pin connector of the fan motor receives a special PWM signal from the motherboard. The fan electronics evaluates the signal and regulates the power permanently according to the requirements. The speed of the PWM fan ranges from 500 - 1,800 rpm. The frame of this Silent Fan is particularly stable and gives the fan a high stiffness. In combination with the high-quality bearings, the fan produces therefore with very little vibration. Apart from the particularly high life expectancy the fan offers a very attractive price-performance-ratio.