Urbuds Bluetooth Headphones V4.1 Wireless Stereo Sports Earphone with Bulit-in Mic APTX for iPhone and Andiord Smart Phones Adoption of high speed bluetooth CSR4.0 standard to ensure lossless and pure stereo sound transmission. Innovated double damping balancing technology and Aptx tech present perfect music and clear communication Plasticity memory wire and 45 degree inclined design,the headphone don't need extra earhook also be stable in your ear. Fast pairing with 2 devices which has bluetooth function,voice prompt and indicator light to monitoring headphone status. No more than 2 hours charge time,but up to 7.5 hours tak time,6 hours music time and 100 hours standby time.