Level one produces amplitude reminiscent of Associate in Nursing warming portable computer and three, a white goods attempting to chill down. The sleep mode additionally produces short and thick noises. I typically have low standards to on-line merchandise however its performance differs greatly from the reviews. This mini fan have four speed level(Low/medium/high/sleep mode) can modify by pressing the ability button repeatedly. The sleep mode will avoid headaches, stuffy nose caused by prolonged sturdy wind and meet the physiological wants of individuals. The fan is nice in doors, however not as nice outdoors in high heat and humidness. i used to be within the shade each days I used the fans. The battery doesn't keep charged as long as represented by 0.5 the time or less. after I had to recharge, the sunshine indicator didn't work properly and once red light went off, seems it hadn't charged fully (very low air on high). I had to use Associate in Nursing external device association to control the fan even for simply some hours. With fan on it's base on a marble counter prime, it vibrated and traveled around not sitting stationary. i believe every individual fan may match higher or worse than another. i'd not advocate. With the 2500mAh reversible 18650 lithium-ion battery, the little battery operated rechargeable portable fan is very transportable as no cable wiring required which may be used each inside and outdoors. Recharges with the provided USB charging cable. Works time for 3-13 hours on a full charge. it's sufficiently little to suit during a small travel nothing tote. whereas very cheap speed isn't up to cool you down, the opposite 2 act. thus far thus smart, because it has been place to smart use this summer, last at a subject park. thus it's a good item to own. With a large vary of USB interfaces, you'll be able to use the USB charging cable link to computers, power bank , laptops and alternative devices to fancy cool wind regardless of wherever you go. it's an honest fan during a heap of how. it's actually powerful enough. But, there's an absence of direction management, thus if you're cooling your face, you have got to carry it at the proper height. the most important is style flaw from my perspective, though it should not be an issue for others, is that the placement of the on/off button. it's right wherever I hold the fan. when i exploit it, I find yourself touching the button which may each increase the fan speed or flip it off. Then you have got to cycle through once more to urge it back to wherever you would like it.