Bluetooth v4.1 provide the most stable connection with bluetooth devices up to 10 meter away. Lightweight design combined with high-fidelity sound perfect for workout and outdoor sports. Advanced cvc 6.0 noise cancellation effectively resists external noise to transmits your voice clearly. Nano-coating and seamless button provide double layers of waterproof protection. Built-in magnet to attach the headphone together and avoid losing them. Magnets design both earpieces are with built-in magnets which can attach to each other like a necklace around your neck when not in use. You will find it most convenient to carry the earphones around for any outdoor activities, such as hiking, cycling, sports, exercise, and more. Intuitive control buit in three remote buttons allow you to conveniently answer calls or skip through music seamlessly at the touch of button. Specifications: bluetooth standard: bluetooth v4.1 operation range: up to 10 meter charging time: 1 - 2 hours music time: up to 6 hours standby time: 150 hours frequency response: 20hz~20khz bluetooth support: hsp/hfp/a2dp/avrcp.