This great pain relieving pad is specially designed for your knee, but can be used on your calf, thigh, arm as well if need be. It has adjustable hook and loop straps closure, it can fit a knee circumference not over 21 inch.
*The heating pad has a built-in mesh bag (5x7"), if need be, put a ice bag in, it can be used for cold compress.
When use the USB cable to plug in an USB port of desktop computer to get source, the output is about 5V/DC.
1 x Knee Heating Pad
1 x USB Cable (2M)
1 X US Plug