Cryorig QF120 Performance 120mm PWM Fan 600-2200RPM Proprietary Quad Air Inlet system features four strategically placed aerodynamic air inlet that allows for extra air intake. HPLN (High Precision Low Noise) bearing system, offering stable and precision rotation eliminating excess vibration and noise. Four pin Pulse Width Modification (PWM) RPM spin speed control ultra wide range RPM settings. Roughly 35% more selection range than the system fans from competitors. *some RPM speeds are only available through PWM control. Integrated Vibration Absorbers built in, nullifies fan vibration. Max 2200 RPM nearly double the airflow of regular 120mm sized fans made for the most extreme overclocks.