Bluetooth V4.0 Enhanced audio & bass response (high quality sound and enhanced bass effect, a top-rate audio experience) Multi-links (HB-905 Bluetooth headset supports a Bluetooth headsets with two phone at the same time connection) Compatibility: works with Android, Apple, and other Bluetooth enabled devices Patent of appearance design Unique, fashion and comfortable wearing style, portability and flexible neck-around (ensuring you comfort throughout the day-wear the around-the-neck wearing style all day without realizing you even have it on) Extensible earplugs design that headphone line will come back through one click, it is flexible and convenience Display headphone's battery on the iPhone, Android and other Bluetooth enabled devices Pause the music & play back automatically when receiving an incoming call Automatically connect to the last connected Bluetooth device Vibration reminding when phone call comes in Echo reduction and Siri function support Safe driving, call clarity It is your best choose for running, gym, hiking, outdoor sports  Accordingly reduce some "electromagnetic radiation" Power on/off  Play/pause track Answer/drop calls Dial the last call from your call records Box size: 19.8*16.5*3cm  Weight: 0.15kg Pcs/ctn: 60pcs Net weight: 9kg Gross weight: 10kg