The blackZX220BT Bluetooth HeadphonesfromSonyfeature 30mm drivers, neodymium magnets, and a built-in microphone for hands-free calls. They have a frequency response of 20 Hz to 20 kHz and can be used for smartphones or tablets to answer calls and play music via Bluetooth. The integrated controls enable you to adjust volume and listen to playlists on your device.They feature a swivel folding design that make it easy to store them when not in use or while traveling. The headphones' built-in lithium-ion battery enables 8 hours of wireless playback to keep your tunes playing throughout the day, and they can be recharged via micro-USB, which takes about 2.5 hours to fully charge.Wireless Streaming with BluetoothWirelessly stream your favorite tracks with Bluetooth. Pair your smartphone or tablet with these Bluetooth-enabled headphones, and you can enjoy your music and even control playlists and volume right from your deviceA Built-In Microphone for Hands-Free CallsThese headphones can take calls and issue voice commands even with your phone secure in your pocket or bag. And with a high-quality inline microphone, you'll be able to make and answer calls from your smartphone with easeNFC One-touch for Instant ConnectivityNear Field Communication (NFC) technology makes complex setup sequences a thing of the past. Simply touch selected NFC-enabled devices to the on-body N-mark for a quick, seamless connection, then start streaming content over Bluetooth. No NFC? No problem. You can still manually connect to Bluetooth using your device's settings menuHear It All with 1.18" DriversHear more of the detail in all your favorite songs thanks to 1.18" dome drivers, which deliver dynamic sound from compact, lightweight unitsListen Longer with 8-Hour Wireless PlaybackThese headphones can keep your tunes playing throughout the day