ZDL-9906 Dual-Way Audio Window Speaker Intercom System Wireless Glass Window Microphone for Business Cheap
$27.85Upgrade Feature : There is one more function than ZDL-9908 is that when the internal machine does not want the external machine to speak, you can directly turn off the microphone of the external machine. Or the internal unit doesn t want to let the external unit hear it, you can turn off your microphone….