Rosewill Teflon Nano Bearing IP56 Dust Resistant Splash Proof 120mm PWM Cooling Fan RAWP-141209 Teflon Nano Bearing Technology TNB runs more smoothly with no friction, making the fan silent, powerful and highly durable (200,000hrs) PWM function automatically adjusts fan speeds according to the CPU temperature for efficient cooling and minimized fan noise Fan Size: 120mm Bearing Type: Teflon Nano Bearing Noise Level: 10 - 21.5 dBA Air Flow: 64.75 CFM Maximum PWM (Pulse Width Modulation)