Manufacturer Specifications Primary Function: Home or Office Audio and Video Portable Intercom System Handheld Receiver Specifications: - Screen Size - 3.4 inch TFT LCD screen - On Screen Indicators - Monitor State, Lock/Unlock, Talk, Take a Picture, Increase Volume, Decrease Volume, View Last Picture, View Next Picture, Signal Bar, Battery Bar - Power Source: Internal Battery (3.7V 1250 mAh Rechargeable Li-ion) - Receiving Frequency - 2.4GHz - Wireless transmitting range - 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 - Dimensions: L:102 x W:134 x H:55 (mm) Entry Guardian Transmitter Specifications: - Camera Sensor - CMOS - Light Source - Six (6) Infrared LED lights - Power Source - AC Adapter (100-240V) 50/60Hz - Transmitting Frequency - 2.4GHz - Wireless receiving range - approx. 50 meters (ideal conditions) - Onboard Buttons/Indicators - Call Button, 6 LED Lights. MIC, Speaker, LED Indicator, Power ON/OFF Switch - Dimensions: L:127 x W:95 x D:36 (mm) Peace of mind has a new name - The Entry Guardian wireless video door phone! See who is at your door from anywhere inside your home. Secure and easy to use, it even lets you remotely open electronic doors to let guests in! Know what is going outside while safe and comfortable inside. The Entry Guardian is our newest home security AV intercom solution that lets you be in two places at the same time. The innovative entry monitoring security system bundles a versatile wireless video monitor receiver with a powerful CMOS security camera wireless transmitter for total home and person protection.