1.[ Battery Support]The m51 is equipped with a 500mah charging case,which can charge bluetooth earpiece for nearly 80 hours of music or call time.The single headset can provide 15-20 hours of usage time.Two charging methods to choose,solve the problem of running out of electricity 2.[Dual Microphone Noise Reduction]The noise canceling earpiece with enc dual-mic noise cancellation.CVC8.0 and ENC blocks 96 percent noise effectively eliminates echo for clearer calls 3.[est 5.2 Bluetooth Technology] wireless earpiece features the updated 5.2 bluetooth technology to quickly and stably connect devices in the 15m range.Dual connection to connect two devices simultaneously compatible with ios or android windows etc 4.[One Button Mute]Just need a button to quickly mute the microphone,protect your privacy at any time Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.