This model S6 fan is decent for the 100 and some dollars, appearing to be better made than most others anywhere near the price. There are two negatives points and one disappointing issue.
The specs for CFM and noise are valid, but there is deceit by omission here, since these two specs, 402 cfm and 32 dB, are mutually exclusive. The cfm rating is at maximum speed, and the noise rating is at the minimum speed. Expect another 20 dB at maximum speed. You could get lower noise levels if both sides of the fan are ducted.
The only control is a single push-button. If you are at the lowest of 8 speeds, it takes eight pushes to turn the fan off. A similar exercise is required if you wanted to lower the speed by one notch.
The good part of the controller is that the last speed used is remembered if power is removed, such as with switching the AC power line. The bad part is that the memory is in the corded controller, and without the controller attached, the fan will only run at maximum speed. Despite it's flaws, I am buying more of them, since they move a fair amount of air at the lowest speed, probably well over 100 cfm.