Mini 503 Sport Bluetooth 4.0 Wireless Headphones Music Stereo Earphones&micro Sd Card Slot&fm Radio (Black) Latest upgraded Bluetooth 4.0+APTX Headphones : Low-power & Low-latency provides high-fidelity and stereo music Compatible with most cellphone and devices with bluetooth capabilities. High quality with HD speaker and enhanced BASS effect. Bluetooth transmission distance 10M Flexible design perfect Sport Wireless Headphone  Sweat-proof and rainproof ; Light weight. Support power status broadcast, real-time silent ;Built-in high quality microphone support various phone calls (by Wechat,Skype,MSN)