High performance cooling fan, 92x92x25mm, 12V, 4-pin PWM, max. 1600 RPM, max. 17.6 dB(A), >150,000 h MTTF Renowned NF-B9 high-end 92x25mm 12V fan, more than 100 awards and recommendations from international computer hardware websites and magazines, hundreds of thousands of satisfied users Highly optimised low-noise design with outstanding quietness of operation, static pressure and airflow (CFM), ideal for chassis ventilation, cooling fan replacement for NAS and other devices, etc. 1600rpm 4-pin PWM version with excellent balance of performance and quietness, supports automatic motherboard speed control (powerful airflow when required, virtually silent at idle) Streamlined redux edition: proven Noctua quality at an attractive price point, wide range of optional accessories (anti-vibration mounts, S-ATA adaptors, y-splitters, extension cables, etc.)