BT Specifcation: Bluetooth V5.0  BT Chipse:JL .6936D  BT Profles Supported: A2DP, AVRCP, HFP, HSP.  Operating Distance: 10 meters  Speaker diameter: 40mm  Ilmpedance: 32Ohm  Sensitivity: 102dB at 1KHz  Frequency Range: 20Hz一20KHz  Rechargeable Battery: 300mAh Li-Polymer Battery  Working Voltage: 3.7V  Standby Current:  8mA  Max working electric current: 11mA  Socket: Micro USB (B type)  Talk time: 24 hours  Music time: 25 hours at 100% volume  Standby Time (un-paired): 90 days or more  Charging Time: 2 hours