[EASY CHARGING] To charge the headphones, simply place it onto the charging stand; it will charge and store the headphones at the same time. The Alto Clair 2 can last up to 16 hours on a full charge. [DUAL CONNECTIVITY] With the USB dongle included, Alto Clair 2 allows you to simultaneously connect to both a PC / laptop and your phone. Its multipoint technology helps you switch seamlessly and automatically between both your devices. [FLEXIBLE CONNECTIONS] With the provided USB dongle, AUX cable, or just the built-in Bluetooth, you can connect your headphones to your audio source any way you want. [SIDETONE FUNCTIONALITY] The sidetone functionality allows you to hear and monitor your own voice when using the detachable mic. You’ll know instantly if you accidentally mute yourself or if your voice isn’t coming through clearly, so you’ll be able to easily and quickly make any needed adjustments. [CRYSTAL CLEAR CALLS] The Alto Clair 2 headset features dual mics and a smart algorithm that effectively filters out environmental noise. Your voice will be heard loud and clear in all your calls, no matter how noisy your surroundings may be.