The NF-S12A case fan marks the third generation of Noctua's classic S12 series, which has received more than 250 awards and recommendations in the international trade press. Thanks to the improved blade geometry with anti-stall knobs and the new AAO frame (short for Advanced Acoustic Optimisation), the NF-S12A achieves up to 8% higher efficiency than its renowned predecessor (conveyor performance/noise development). The ULN version, with its super-slow speed options (800/600rpm), allows virtually silent operation and is therefore perfectly suited for ultra-low noise applications and particularly noise-sensitive users. Its outstanding running smoothness, the SSO2 reference class bearing and Noctua's proven premium quality make the NF-S12A an exquisite choice for noise-optimized housing cooling. Award-winning S12 designThe NF-S12A uses the third evolutionary stage of Noctua's classic Straight Blade design, which has provided the S12 series with countless recommendations from hardware enthusiasts and journalists around the globe. Further optimized for even better airflow/noise efficiency, the NF-S12A is the ideal quiet casing fan. Anti-Stall KnobsThe anti-stall knobs of the NF-S12A reduce vortex shedding phenomena in situations with medium to high flow resistance and thus extend the so-called stall margin. This makes the NF-S12A even more versatile than its predecessor and enables better results on heat sinks and radiators. AAO frame systemNoctua's AAO (Advandced Acoustic Optimisation) frames have integrated vibration buffers, a stepped inlet area (Stepped Inlet Design) and an internal surface microstructures for even better performance/noise efficiency. Stepped Inlet DesignThe stepped inlet area of the stepped-inlet design creates more turbulence in the inlet. This facilitates the transition from laminar to turbulent flow, which adheres better to the frame (flow attachment) and thus increases the suction capacity of the fan, especially when the intake area is limited.