Product paremeters:
Parameter: product model: A-14 
                   Color classification: Obsidian black, moonlight white 
Connect: Bluetooth 5.0, effective distance about 10m
Audio frequency: Earphone sound quality: subwoofer 
                              Earphone material:ABS+PC
                              Loudspeaker unit: composite copper ring loudspeaker 
Endurance: Earphone battery: 45mah
                    Battery of charging case: 250mah 
                  Music playing time: about 4 hours 
                  Earphone charging time: about 1 hour 
Charging time of battery compartment:about 2 hours