Denon AH-W150BU Exercise Freak In-Ear Headphones, Blue Integrated Amplifier Professionally tuned to heart-pounding bass to energize your workout. Bluetooth 3.0 Wireless Connectivity. Rechargeable Battery for long workouts (7 hours). Flexible Neckband, Articulating In-Ear Design provides superior fit. Sweat-Proof Earpiece with Built-In Air Cushion for extreme comfort and ventilation. Anti-Microbial Ear Tips reduce the buildup of bacteria (XS, S, M, L). Integrated Controls & Microphone for on-the-go use. Reflective Back Band for safe evening workouts. Connectivity Technology: Wireless