... field 300 meters 2.4GHz Digital Wireless Video Door Phone* DIY Easy to Install * Able to view, talk and unlock the main entrance ... handfree video color monitor * Infra-red camera on outside call station - see callers at night * Intelligent remote unlock for visitors ... - 20mA~30mA (standby), 190 mA (operation) Audio Input - 12-digits digital audio signal, DAC interface, 8Kbps sampling speed rate Image ...