Buttons for controlling and answering calls: volume, song switching, pause function. Bluetooth version 5.0. Built-in 500mAh battery. Up to 8 hours of music playback and 18 hours of standby time. Built-in mp3 player memory card input. Panel with function buttons. Clear playback sound. Built-in HD microphone for phone calls. Foldable design for easy carrying and storage. Soft ear cup and headband finish. Improved sweat resistance. Frequency range 20Hz-20kHz. All products are REACH, ROHS and CE certified.