i360 v4.0 Headphone Beanie Compatibility: Designed for 6th & 7th Generation Apple iPod Nano. Compatible with 2nd and 4th generation iPod shuffle. Also compatible with Nike + iPod system. The i360 includes an internal 3 jack wiring system with detachable speakers allowing for easy disconnect when washing. While the usual over the ear speaker lacks, i360 designed custom speaker casing provides optimal sound quality and bass response for peak performance maximizing airflow with no distortion Outer material: 100% Acrylic, Inner material: 95% Cotton 5% Spandex. Black with Red Tag (One Size Fits All)