Review on 💨 ELUTENG 40mm USB Fan: Powerful 3-Speed Control Ventilator for VR, PS, Xbox, PC Cabinet Cooling by Temarquis Lopez

It makes a constant buzz when low or high. The higher the fan speed, the louder the hum. At night I set it to a minimum and do not disturb sleep. During the day I use it at an average level, and although I can hear it, it easily dissolves into background noise on reflection. I use this little fan in my 12x12x12 terrarium to keep air circulating. I have an 80mm fan, but I think it's too much for such a small tank, even at low speed, so the 40mm fan provides the necessary circulation. I am happy with my purchase.