QuietPoint® active noise-cancelling technology greatly reduces environmental noise Bluetooth wireless technology with mic and controls built into the earcup for convenient handling of calls, music playback and volume adjustment 40 mm drivers deliver high-fidelity audio reproduction 1.2 m (3.9') cable provides a wired connection for times when wireless operation is not available or when battery power is low Foldable design makes headphones ideal for travel Up to 20 hours of continuous Bluetooth and ANC use on a full charge Includes 30 cm (1') USB charging cable