Noctua NF-A9 PWM, 4-Pin Premium Cooling Fan (92mm, Brown) Award-winning 92x25mm A-series fan with Flow Acceleration Channels and Advanced Acoustic Optimisation frame for superior quiet cooling performance Ideal for 9cm CPU coolers (e.g. Noctua NH-U9(S) & NH-D9L series), compact PC cases (HTPC, ITX, Small Form Factor), replacement fan for NAS and other devices, etc 4-pin PWM version for automatic speed control via 4-pin PWM fan headers, broad 400-2000rpm speed range (1550rpm max. with supplied Low-Noise Adaptor) Includes anti-vibration mounts, fan screws, Low-Noise Adaptor, extension cable and y-cable for running two PWM fans on the same header Trusted Noctua quality with premium-grade SSO2 bearing and more than 150.000 hours MTTF