Silent operation. And very durable
It works almost half the day non-stop and so far it hasn't made a sound nor has its power dropped

When I opened it, something was shaking inside. I realized that the motor was not screwed onto the base, so the whole fan was rubbing against the sides. I reassembled it with two screws of my own that fit. It works satisfactorily at low speed, but at high speed, the blade hits the side and it is very annoying, so it is useless. Obviously, someone bought it before me, had the same problem at high speed, and returned it, missing the two screws. The supplier either didn't notice or... Because it works fine at low speed, I didn't bother to return it.

I used it with a 1.5m extension for ventilating a closed basement space of 12sqm. The motor was placed 1.5m away from the grilles in the area I wanted to ventilate, and its sound is minimal. Essentially, you can hear more the air swirling inside the 125mm PVC pipe up to the fan, rather than the motor itself. I don't think it actually pulls 240 cubic meters of air per hour as stated by the company, but it does its job correctly and the space doesn't smell like smoke or mustiness (the space is underground). At 50-60€, it's a very good solution for simple uses.

The construction quality is relatively good, but the reason I am giving it 3 stars is that while the turbo φ125 I bought claims to be 50 watts on the high setting and around 35 watts on the low setting, measured with an electronic consumption meter, it is actually 35 watts on the high setting and 25 watts on the low setting. In the end, the exaggerations of Chinese numbers are everywhere

Quite powerful in both speeds, a little bit noisier but for an outdoor space it's not a problem

It works continuously. It doesn't pull with a lot of force, but it's okay. At some point when I disconnected it, I had to give it a push with my hand to start the propeller. It may have had difficulty due to the accumulation of dust, moisture, and ink that it absorbs from the space it was placed in.