The popularity of the USB cooling tray is do to their ease of use. You do not have to hunt around for a wall outlet to plug into; the outlet is right on the laptop. You just plug it in an turn it on
Because it is something which is widely used to transfer data. its convenience of plug in and use has made it very popular.
8 times 4 is 32 so if you use four trays you'll have room for 2 more sandwiches.
you can get a USB at any Walgreen's for about 10 dollars or so depending on how much the USB holds.
The USB Powered and Most Efficient Metal Cooler Pad with 3 Built-in Fans is really great but no back so use it on a tray.
yes
so you can know where everything is when you need it
USB power strips work with any USB wall charger so long as the device can charge over USB.
they provide a space specifically for hot items so that you or other people don't burn themselves by accident, they allow air to circulate in between the trays and cool them faster, and they prevent counters from becoming hot or melting.
A USB printer is connected to a computer or network by a USB cable - so the answer is "No!"
Do you mean do usb devices work on an airplane? If so then yes.
Only a CD and Casette input! So no USB.
cooling fan is so important for pc .