... applicable to scene monitor and wirelss audio transmission,such as security monitoring system,hidden interview,audio-visual eduction,tourism,amusement,field ... which can be used for 16 hours in total.the receiver uses two 7th batteries of 1.5V which can de ... on the characteristics mentioned above. Package List:1*Audio Transmitter1*Audio Receiver 1*User manual-English 1*Power Adapter(100-240V, 50 ...