Green Lion Echo Max Headphone

-Charging: USB-C / USB-A cable included
-Autonomy: 50 hours at 50% of the max volume in Bluetooth mode
-Integrated battery: Lithium-ion polymer 3.7V 500 mAh
-Headset sensitivity : 102 dB + 3 dB
-Frequency range: 20Hz – 20kHz
-Signal/noise ratio : 90 dB
-Maximum range: 10m
-Impedance: 32Ω
-Bluetooth: V 5.3