Puro Sound Labs BT5200 Studio Grade Bluetooth Wireless Headphones - The Healthy Headphone (Black) THE WORLD'S ONLY HEALTHY EARS HEADPHONE: The only headphone with advanced volume monitoring and interactive reporting system to guide users to safer listening. PURO BALANCE RESPONSE STUDIO GRADE AUDIO: Crafted with 40 mm custom dynamic drivers, we recreate the best sound you have ever heard into a headphone experience. UP TO 24hrs BATTERY LIFE: Listen to music for hours and hours, not worrying about having to recharge. 200 hours standby means even greater convenience. DURABLE LIGHTWEIGHT ALUMINUM DESIGN: The aluminum used in the ear cups and headband insure that the BT5200 headphones will last far longer than competing products made from cheap plastic. It also makes them lighter and gives them a higher quality look and feel. AMBIENT NOISE ISOLATION: Blocks 82% of Background Noise