Top features:- Bluetooth connection for wireless listening – Carry case with built-in battery for on-the-go recharging- Built-in microphone for handsfree callsBluetooth connectionEnjoy great sound anywhere, without the hassle of tangled cables. Goji GTCBTTW17 Wireless Bluetooth Headphones can pair with your smartphone, or any other compatible device using a Bluetooth connection.It takes just seconds to pair the headphones. Once you do, you can listen to all your music for up to three hours on a single charge – long enough to keep you entertained on the journey to work and back.Carry case with built-in batteryListen for longer, thanks to the included power bank and carry case. It acts as a spare battery to recharge your headphones. It’s a real lifesaver when you need a little music to liven things up, and your charge has run out.Built-in microphoneAnswer calls on-the-go without having to dip into your pocket for your phone. The GTCBTTW17 Wireless Bluetooth Headphones have a built-in microphone so you can answer calls in an instant.