100% solid copper keep in mind that this product will tarnish.

Some people will experience their wrist turning green, it depends on your body chemistry and it does wash off. some say that it shows that the copper is working. It is the copper combining with sweat and it cause a reaction with chelates which are in your body. It is said that when there's a lot of green on your skin from your copper bracelets that you are stressing and that's a sign that you need to slow down.