Sony MDR-RF985RK Wireless Radio Frequency Headphones (case of 2) Enjoy high-fidelity sound, at home, in wireless freedom Wireless radio-frequency transmission provides quality indoor transmission. (Up to approximately 150 ft) The easy-adjust headband allows for long-term comfort and ease-of-use Quick charging your headphones is a breeze with the secure charging system. A 3.5 hour charge will produce a full charge of approximately 25 hours 40mm drivers deliver deeper bass and audio clarity for a superior home entertainment experience