The M20xBT (ATATH-M20XBT) are Over Ear wireless headphones featuring powerful 40 mm drivers for enhanced low-frequency performance. They provide up to 50 hours of continuous use on a full charge and up to 3 hours of use on a 10-minute rapid charge (via USB-C connection). The headphones are easy to operate with a microphone and buttons built into the left earcup for convenient handling of calls music playback and volume control. We ve also included a 1.2 m cable so you can use M20xBT like a standard pair of wired headphones when desired.