Next-gen 140x25mm design for unprecedented quiet cooling performance in both high airflow and high static pressure applications: ideal as a PC case fan, on CPU coolers and water cooling radiators! State-of-the-art engineering (Progressive-Bend impeller with winglets and Centrifugal Turbulator, Flow Acceleration Channels, AAO frame) and construction (Sterrox LCP, ultra-tight tip clearance) Ultra-quiet 4-pin low-speed PWM version with 800rpm maximum speed, ideal for semi-passive setups (fan stops at 0% PWM) or ultra-low-noise applications that require PWM control Includes anti-vibration mounts, 14cm anti-vibration gasket for tighter seal on radiators, fan screws, Low-Noise Adaptor (LNA), extension cable and y-cable for running two PWM fans on the same header Trusted Noctua quality with premium-grade SSO2 bearing (MTTF > 150,000 h), safety certifications from UL and TÜV, protected against reverse polarity, over voltage and over current (short-circuits)