Utilizing decades of audio expertise, the Marshall Major IV Wireless On-Ear Headphones (Black) are engineered with custom-tuned 40mm drivers that are made to deliver natural sound with booming bass. Whether you're enjoying your favorite album or latest podcast, you can do so for days without ever needing to recharge. When the power does run low, you have the option of either wired or wireless recharging. The audio you hear is streamed via a Bluetooth-compatible device, and if that's your smartphone, you get the added ability of making hands-free calls. All of this audio tech is wrapped in Marshall's rock-and-roll style.