The patch that comes with it to stick to your feet is perfect size,it went on easily and was quite comfortable. I wear a 12 shoe size. When you wake up in the morning they do leave your feet a bit sticky and you have to rinse them, however I didn't find the residue hard to remove and it came off easy with just water.
The reason I have it 4 stars is because I'm not sure what benefit I got from them. Felt pretty much the same in the morning and the black shown in the photo appears to be just where the stuff inside got wet. The stuff inside the patch is already black. That being said, when I was falling asleep I did feel a bit tingly in my legs, so it might have been working some sort of magic, who knows.
All in all, it was a fun experience and I felt like I was pampering myself, so I enjoy it.