"The black case fans from the Xilence White Box series are excellent value for money.
Savings have been made on the packaging but not on features that determine quality, like the fluid bearing and noise-optimised design.
Features:Optimal performance in any situationFan with fluid bearingAir flow-optimised rotor bladesTechnical data 40 mmFan dimensions: 40 x 40 x 11 mmConnection type: 3-pinVolume: 19 dB(A)PWM: noFan bearings: fluid bearingAir flow: 6.9 CFMFan speed: 4500 RPM ± 10%"