... DC jack pinhole monitor china factory, Mini Audio monitor with 160metres monitor range,0.2g,14x4.2mm ... s also very good to surveillance. 2, High sensitive pickup. It is a professional product specially ... range is up to 160 square meters. 3,High sensitivity, low noise, low distortion, small size, ... highway toll station when it is connected with a wireless repeater.6,Cable connection, red-- power supply ...