Award-winning 80x25mm A-series fan with Flow Acceleration Channels and Advanced Acoustic Optimisation frame for superior quiet cooling performance 8cm format is ideal for compact PC cases (HTPC, ITX, Small Form Factor) and other chassis (intake & exhaust), replacement fan for NAS and other devices, etc. 4-pin PWM version for automatic speed control via 4-pin PWM fan headers, broad 450-2200rpm speed range (1750rpm 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, backed up with 6-year manufacturer-warranty