Very good but ... surprise

It has two modes: a "Power" has 12v and "Silence" has 7V

Be aware that mode power at 12V, the airflow is huge !! it impressed me! the blow to circulated air it's great, it can inject a lot of air spawning or extract a lot of hot air!
The blue LED is also very beautiful! Beautiful effect
The problem is that it makes a lot of noise! But it's not the fan noise that turns that have meant! But the air flow passing! It is so important that it made a lot of noise (such as ventillo up to us to cool us)

Then comes the silent mode, which is obtained by adding the supplied extension cable that contains a resistor for 12V has spent 7V: And indeed we hear more or almost the fan (for me I can not distinguish the other by noise) So great!
The rotating fan slower sudden, the air flow is reduced but still very correct: for example I plugged the fan on the side door of my tower in silent mode: My CPU and GPU were down 10 ° C nothing but add this fan! So it suits me me.
The problem I find to say is that suddenly the LED shines very little! and suddenly there is very little light coming out of the Tour! that I am disappointed because I had to buy a fan to light that it shines into my lap ... But it shows 12V good!
It would have been to separate the reduction of the Volt LED fan! So one star less for these!

Nevertheless this fan is very good!
having two possible speed allows for control over the cooling tower it!
ex: Usually your fixed Pc performs well and the component have a good temperature -> you put the fan silent mode, allowing a flow of air without the inconvenience of noise!
Then one summer there is a heat wave, your room is an oven and your component exceeds normal temperatures or through extreme temperatures -> you pass the fan power fashion! You have the noise but the air flow will be very hard to further reduce the temperature of your component!

So I'm not disappointed in this product that allows manual adjustment with two mode as needed compared to others where you can not change!
Hic is only LEDs that light loss on the 7V

PS: I also add a dust filter associated with the fan, you should know that the rubber leg to the vibration does not allow to associate the filter + fan, so to force the screws!
But with the screws 7V (I did not try the 12V) I do not perceive any vibration!
But now I wondered if it was going to last well no bad ^^ but not affect!

So personally I would recommend the product =)