Bluedio T2 Bluetooth 4.1 Hi-Fi Foldable Stereo Wireless Headphones Built in Microphone Support SD Card Playback FM Radio T2 Dedicated Android App - Black Auawak Bluedio T2 stereo headphone using Unique folding mode for volume minimisation you can rotate the ear cup up to 195, easy to carry and save more space.. Therefore, it is the perfect travel companion. Bluedio engineers have spent two years in creating T2 Ultra-big speaker, diameter up to 2.24 inches, trying to bring you the best music experience: rich and b bass, crisp and clear highs. It's the latest Bluetooth chip, which can transmit data at high speed and bring you smooth music experience. And its low power ensures long lasting battery life: up to 40 hours continuous music time. Its ear cup and headband top are padded with sufficient foam and covered with soft leather. What you may not notice is that we adjust the headband, based on Ergonomics theory, to fit all head sizes.