bluetooth headphone HK Astrum Raga BT

specification:
Bluetooth specification: V2.1 + EDR
Bluetooth profiles supported: HSP, HFP, A2DP and avrcp
Operating distance: 10m class 11
Playing time: Music-up to 5 hours; talk-up to 9 hours
Standy time: up to 180 hours
Charging time: about 3 hours (first time: 5 hours)
Dimensions: 162*153.5*32
Weight: 103g
Package content: USB cable, manual, the speaker
Materials:ABS
Finish: Coated rubber
Capacity: 180mAh
Working voltage: 3.7V
Maximum charging voltage: 4.2V, EODV
Cycle life: 450 times
Parameters:
Loud speaker: X
Magnet Type: Inside Magnet
Size: DIA=30
Thickness: 7mm
Impedance: 37Ω
Frequency Response: 20-20KHz
Sensitivity: 123±3dB
Rated Power: 15mW
Harmonic distortion: ±3dB