Enjoy your favourite music free of distractions with wireless noise cancelling headphones. Stay on the move with hands free calling and 35 hours of wireless playback on a single charge, or up to 50 hours of playback with wired listening using the supplied cable. Optimize noise cancellation or connect to your smartphones voice assistant at the push of a button. Neodymium Magnet Cord Length: Approx. 3.94 ft (supplied headphone cable); Frequency Response: 7 Hz–20,000 Hz; NFC: Yes; Cord Type: Detachable Single sided type; Volume Sensor: Yes. Battery Life (Waiting Time) : Max 200 hrs (BT: ON/Noise Cancelling: OFF) Few easy troubleshooting steps for better experience: Make sure that the noise canceling function is turned on (the indicator (green) next to the NC button lights up). Adjust the earpad position to fit your ears. The noise canceling function is effective in low frequency ranges such as airplanes, trains, offices, near air-conditioning, and is not as effective for higher frequencies, such as human voices. Initializing the headset to restore factory settings Disconnect the micro-USB cable, turn off the headset, then press and hold the button and button simultaneously for more than 7 seconds. The indicator (blue) flashes 4 times ( ), and the settings such as the volume adjustment are reset to the factory settings. This operation resets volume settings, etc., and deletes all pairing information. In this case, delete the pairing information of the headset from the Bluetooth device, and then pair them again. If the headset does not operate correctly even after initializing, consult your nearest Sony dealer.