Gym Sport Running Workout Sweat-resistant Armban Case Cover for Nokia Lumia 521 T-Mobile by CyberTech (Color: Blue) This armband is made of neoprene material. It is sweat-resistant, water-resistant, and washable. With the Clear Plastic Cover, you can operate your full touch screen easily. It has a built-in key slot with no added bulk and it works with most cases. It is lightweight and durable. It is compatible with Nokia Lumia 928 / 520 / 521 / 925 / 1020, (Screen size up to 5"). It fits arm width from 6" ~ 16". Color: Blue