... 3.5 inch screen Color Hands-Free Digital Wireless Video Door Phone System Primary Function: Home or Office Audio and Video ... range - approx. 250 meters (ideal conditions) - Onboard Buttons/Indicators - Unlock Door, View Monitor. Talk Button, MIC, LED Indicator, Mini USB Input ... , Speaker, Volume -/+, Brightness control -/+, Antenna, Power ON/OFF Switch - Dimensions: L:102 x W:134 x H:55 (mm ...