Silent Wings 4 PWM Highspeed, 9 Blade, 2500rpm, 76.7CFM, 31.2dB, Fluid Dynamic, 4-Pin PWM. Fans 40mm - 120mm be quiet! 120mm Silent Wings 4 PWM Highspeed PWM Quiet Fan. A 6-pol-motor and anti-vibration mountings combined with fan blades optimized for maximum airflow make Silent Wings 4 120mm PWM high-speed the perfect choice for the most demanding applications in high-end systems.
