I have an Opolar WH110. Next week will be four years. It is 8", has a 10000 mAh battery, and charges from USB. I bought it for my van but use it in the house in the summer for spot cooling at my desk or at night. It will run on low for 2 days, is fairly quiet, and has a swivel clamp that also acts as a stand. I rarely use anything but the lowest speed and that can be easily felt across a 15' room. I'd buy another one for the house when our small 110v fans finally die. Only negative was the $43 price back then, but I think the value is there.