Bluetooth v 4.1 - Quick and easy connection to any Bluetooth device ^^ Built-in Microphone - Stay connected to your mobile with hands free calling ^^ Internal Li Ion Battery - Rechargeable battery for up to 12.5 hours listening between charges ^^ Music, Volume and Call control Buttons - Answer calls and control your music ^^ Bluetooth Wireless NFC Headphones - Listen to audio from smartphones and tablets, tap to connect to NFC enabled devices