This is a very unsual heat patch that's tailored to hug you knees. It has sections of pouches that are filled with six types of natural medicinal herbs for moving blood and Qi, which is accelarated by the self heating mineral. Two super soft elastic bands makes it easier to adjust around the shape of your knees. 

Suitable for knee tiredness, stiff knees, cold knees, arthritis, sports injury... 

The moxa and ginger essense oil adds extra effect and is sold separately. Two bottls of essense oil come free if bought a full box of 26 pieces.