The QCY H4 provide an amazing sound experience. Equipped with 40-millimeter drivers, they reproduce sound of the highest quality, certified by Hi-Res Audio. Active noise cancellation technology effectively eliminates outside sounds, allowing you to focus on what matters most. They allow music playback for up to 70 hours, and dual microphones combined with ENC guarantee clear phone calls. You'll connect them to the device of your choice either wired or wirelessly. The dedicated QCY app will allow you to customize the sound settings for any type of music. Top-quality sound. With the QCY H4, you'll experience sound like you've never heard before. With 40mm drivers and a wide frequency response of up to 40kHz, the QCY H4s deliver incredibly clear and precise sound. They are also Hi-Res Audio certified to reproduce studio-quality sound. Now you can hear every detail of your favorite songs - from deep bass to the highest tones. Forget the noise. Immerse yourself in the sounds of music or focus on your work, no matter where you are. With ANC technology, the earphones reduce ambient noise to as much as 43 dB. That means you can enjoy your music without the distracting sounds of the street, office or other distractions. The QCY H4 also offers four ANC modes, which vary in the level of muting of outside sounds. There's also an Ambient Sound mode, which allows you to stay in touch with your surroundings without removing the earphones, which is useful in city traffic, for example.