Retractable hidden microphone arm Multiple microphones Acoustic Shield Technology 3 levels of ANC Excellent audio experience and all day wearing comfort Up to 40 hours of battery life Qi wireless charging Flexible switch between on-ear and over-ear Dual-side busylight for full visible angles Bluetooth Business Headset BT51-A/BT51-C USB Dongle 1.2 M USB 2.0 USB-A to USB-C Cable Drawstring Bag Black for Headset On-ear Cushion Quick Start Guide