Get the freedom to leave your desk while on a call. Wireless Bluetooth technology 1.5 gives you up to 30 meters / 100 feet of hands-free connectivity to PC, smartphone and tablet. Get up to 10 hours of talk time on a single charge. Or simply connect the USB the cable and charge while using the headset. Simply wear the headset to eliminate high-frequency noise, such as human voices - all thanks to the specially designed ear cushions. We call this "passive noise cancellation."