Dedicated dual fan set with two NF-A14x25 G2 PWM 140x25mm fans that are slightly off-set in speed (+/- ~25rpm) in order to avoid undesired acoustic interaction phenomena ^^ 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) ^^ Ideal choice for push-pull applications as well as situations where two fans are operating side by side (280mm water cooling radiators, case intake or exhaust fans, etc. ) ^^ All-black chromax version with black anti-vibration mounts, 14cm anti-vibration gaskets for tighter seal on radiators, fan screws, Low-Noise Adaptors (L.
N. A. ), extension cables and splitter cable ^^ Trusted Noctua quality with premium-grade SSO2 bearing (MTTF > 150, 000 h), safety certifications from UL and TUV, protected against reverse polarity, over voltage and over current (short-circuits)