Size: Small (20.25 cm circumference, 9 cm height) Medium (25.40 cm circumference, 9 cm height) Large (30.45 cm, 9 cm height) Made of: 80% Nylon / 20% Spandex armband with a sewn in mesh pocket to hold any Flex, Kailo, or Element pain patch Comes with: Comes by itself with an instruction card Product Highlights: – One time size exchange available within 30 days of purchase – No-hassle size exchanges – 3 available sizes (small, medium, and large) – For use on your upper arm – Keeps your pain patch in place with no need for adhesives – Soft and flexible – Helps extend the life of your pain patch – All sizes stretch at least 50% *Patch not included. Remove patch before washing. When putting the armband on, the patch should be placed over the triceps muscle. Rotate it to find the perfect placement. Please contact customer service with questions.