Specification of bluetooth
Bluetooth version: V3.0+EDR
distance: 10m
Range of frequency: 2.4-2.4835GHz
TF card supported: 128M-32G
FM frequency response: 87.5-108MHz
Specification of headphone 
Speaker: ￠40mm
Sensitivity: 115dB S.P.L at 1KHz
Impedance: 32ohm
Frequency response: 20Hz-20KHz
Rated power: 40mW
Cable length: 1.5m
Microphone Unit: 4.5mm×2mm -58dB±3dB
Plug type: ￠3.5mm stereo
Rechargeable lithium battery: 550mAh
Charging time: less than 3 hours
Normal volume playing time: 10h
Standby time: 180h