Nathan SonicBoom iPhone Secure your iPhone for an entertained run with the Nathan SonicBoom iPhone Armband. Offering an easy-touch window, this running armband helps protect your iPhone without limiting functionality. The sleek Ergological™ design integrates NDurAthletic™ and moisture-wicking technology to keep skin cool, dry, and comfortable. Hybrid polyurethane and performance textile material offers long-lasting durability. Reflective details increases visibility in low light up to 1200 feet.