Avantree Audition, featured with Bluetooth 4.0, over the ear design which will be much more comfortable. With NFC function, you can touch your phone to it and the headphones will turn on, connect or disconnect. They are light weight and stylish. It can connect two devices and the battery lasts forever (up to 40hrs)! Even if the headset is out of battery, you can plug them in with the 3.5mm audio cable and use it as wired headphones! Product Features *Bluetooth 4.0 stereo headphones for wireless music steaming. *High-fidelity stereo sound quality with aptX codec. *Long music time-up to 40hrs. *Easy one touch pairing with NFC technology. *Additional audio line input, for use when battery is low. *Never miss a call - auto switching between music and calls. *Ultra-soft over the ear pads with adjustable headband. *It can connect to two phones. *Gaming and chat and VoIP (Skype, MSN, etc) Specification *Bluetooth V4.0 with EDR *Supports profiles: headset, handsfree, A2DP, AVRCP *Operation range: Class 2, 10 meters *Up to 40 hours music time and 20 days standby time *Headset size: 180mm x 170mm X 80mm *Inner diameter:5.5cm(length) * 4cm(width) *Outer diameter:9.5cm(length) * 8.4cm(width) *Headset weight: 180g What"s in the box *Avantree Audition Bluetooth stereo headphones *Micro USB charging cable *3.5mm audio cable *Warranty card *User manual Compatibility Compatible with all the Bluetooth enabled mobile phones. Warranty 12 months quality warranty for normal use from us directly. Contact Avantree Support for this. Support If have any problem, contact us Mon-Fri 9:00AM-5:00PM. Emails answered within 1 business day.