Pros below: Materials, plastic with marks on the material used, and compliance with the requirements . Beautiful, it works rather quietly, despite the fact that one of the two purchased is poorly centered, it can be seen that it drives the impeller and there is vibration when turned on, BUT thanks to the rubber mount of the rotor, it does not have a critical effect on the noise and the beating of the fan itself. Didn't use it for a long time, just installed it. Got cons: bought two. in one of the beating of the fan impeller is present, but not critical, because. mounting and rotor technology allows to dampen negative vibrations, even in a "slightly" fixed housing.