Denon's Exercise FreakTM In-Ear headphones are the ultimate, super-lightweight, sweat proof, wireless fitness headphones that perform the way you do. Listen to your favorite music & answer calls without the inconvenience of cables getting in the way of your workout. These headphones have been tested by frequent exercisers and found to be the most comfortable and provide the most secure fit. Also Included: Mesh Carrying Case with Karabiner, Micro USB cable (for charging battery), and Anti-Microbial Silicon-Ear tips (XS, S, M, L). Further enhance your workouts by downloading the Denon Sport application, available for smartphones.