*Loudhailer diameter:40mm
*Frequency range:20~20000Hz
*Sensitivity:102dB
*Impedance:32 Ohm
*Maximum power input:60mW                                                                            

*Plug(mm):3.5 Stereo                                                       

 *Power Supply: build in 3.7V Lithium Battery                                         

Charging:USB 5V adapter                                             

Reciever distance:15 meters