Stretch material. There are 5 1000 gauss-ferrite magnets that have unique alternating arrays. There are pressure points to keep you relaxed and to maintain concentration in the wrists so that it helps improve mental concentration; especially, when putting in golf. Also, the wristband is adjustable and can be worn on wrist as well. We are well known for this product. Our customers have said, "My stiff shoulders feel better." "Pain in the elbow is much better now." When wearing it on the ankle, it will help to relieve ankle pain or dullness. This is very effective for hiking. This helps stimulate blood flow from wearing the wristband.