4-Pin PWM fan with standard case   Perfect Case Fan Regulation with PWM The PWM function allows the motherboard to run the fan precisely at its necessary speed. This guarantees the required cooling and minimizes the noise level.     Patented PWM Sharing Technology (PST) Lowers Noise If you want to improve the cooling efficiency of your computer you get several case fans working in parallel (since it takes 10 fans to double the noise level). But what does it help if they dont work together? The PST assures that all of your fans listen to one control signal. E.g. you share the CPU Coolers PWM signal and assure that your case fans stand down at low load and spin up whenever necessary.     Innovative Design Enables Quiet and Efficient Ventilation The innovative design of the fan blades improves the air flow and facilitates a highly efficient ventilation. The impeller was designed with a focus on minimzing the noise level yet delivering the desired airflow and pressure.     Two Way installation Blow warm air out of the case Draw cool air into your case Specification Type: 8cm Case Fan AMD/Intel: N/A Fan Connector(s): 4-pin Installation: Screws LED Lightin No Colour: Black & White Weight: 72 g Fan Dimensions: 80 x 80 x 25 mm Dimensions: \"up to 2,000 RPM\" Fan Controller: PWM Rotation Speed: \"up to 2,000 RPM\" Fan Bearin Fluid Dynamic Air Flow: \"31 CFM / 52.7 m3/h (@ 2,000 RPM)\" Noise level: \"0.3 Sone (@ 2,000 RPM)\" Power: 12V DC Package Weight: 0.4240 kg Warranty: 6 Years