Never used. Slate Blue Sony Headphones Experience superior sound with the Sony WH-CH520 wireless headphones, designed for comfort and convenience. These slate blue headphones are perfect for anyone looking for headphones for work or enjoying music, audiobooks, and podcasts. With an impressive up to 50-hour battery life and quick charging, you'll have plenty of power for those multi-day road trips and long festival weekends. Customize your audio experience with the EQ feature found on the Sony | Headphones Connect app, and enjoy enhanced sound quality with DSEE™ technology. The built-in microphone offers crystal-clear hands-free calling, and with multipoint connection, switching between two devices is a breeze. Compatible with 360 Reality Audio for an immersive experience, these lightweight headphones are easy to carry with a swivel design and are environmentally friendly, as they are partially made from recycled plastic. Find your headphones quickly with Fast Pair and easily connect to your PC via Swift Pair. Elevate your listening experience today with Sony WH-CH520 wireless headphones; comfort and quality are just a purchase away!