... - approx. 50 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 Small Receiver Dimensions - L: 140 x W: 86 x H ... .chinavasion.com/security-gadgets/double-vision-guardian-wireless-video-door-phone-with-dual-receivers-cmos-sensor/OR>>http://www. ...