The NF-A9 is a highly optimised, premium quality quiet 92mm fan. Featuring Noctua\'s AAO (Advanced Acoustic Optimisation) frame as well as sophisticated aerodynamic design measures such as Flow Acceleration Channels, the NF-A9 further improves the renowned quiet cooling performance of the award-winning NF-B9. The PWM version sports Noctua\'s custom designed NE-FD1 IC for fully automatic speed control via 4-pin fan headers and comes with a Low-Noise-Resistor Adaptor to reduce the maximum speed during PWM control from 2000 to 1550rpm. Its superb running smoothness, reference-class SSO2 bearing and Noctua\'s trusted premium quality make it an elite choice for the highest demands.Specifications:- Dimensions: 92 x 92 x 25 mm (W x H x D)- Material: Plastic- Normal mode: 400-2000 U / min, 22.8 dB (A) 78.9 m / h, 2.28 mmH2O- With LNA: 1,550 rev / min, 16.3 dB (A) 62.6 m / h, 1.53 mmH2O- Voltage: 12 V- Power consumption: 1.2 W, 0.1 A- Connector: 4-pin PWM- Life expectancy 150,000 h- Manufacturer Warranty: 6 years- Accessories: - 1x power Adapter (LNA) - 4-pin Y-adapter - 30 cm extension cable - 4x Fan screws - 4x Vibration inhibitors