Coocheer Rechargeable Slim Stereo Wireless Bluetooth Headphones & Hands free Calling Headset Bluetooth v4.0 - 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 bluetooth playback time listening between charges Music, Volume and Call control Buttons - Answer calls and control your music: play, pause, previous/next, volume up/volume down Bluetooth Wireless NFC Headphones - Listen to audio from smartphones and tablets, tap to connect to NFC enabled devices