SLIM & LIGHTWEIGHT : Made of a quick-drying Lycra cloth, the flexible arm sleeve is lightweight and easy to fit on your arm. Other phone armbands are bulky, uncomfortable and rub your skin during exercise. Our soft and comfortable material will hold your phone secure with no pinching, no irritation and no distractions. KEEP YOUR PHONE CASE ON : Never leave your phone behind with the secure armband that can hold your phone with a case ON. Whether your phone is 4"or 6" tall, the band will hold secure with no bounce. SMALL - LARGE ARMS : Finally, a phone armband that you never have to readjust or worry about slipping during physical activity. The comfortable material hugs your arm like no other armband you've used before. Please measure around your bicep circumference (Before Ordering) for a guaranteed fit. X-SMALL 7" - 8.5", SMALL: 8.5" - 10.7", MEDIUM: 10.7" - 13.0", LARGE: 13.0" - 15.1", X-LARGE 15.1" - 17.1"