Plug and play and expandable to 4 cameras: Baby camera is plug and play, no configuration required. One parent unit monitor can be paired with 4 child unit cameras. (A monitor and camera included) You could take care of all your kids with one monitor Stable private signal: Using 2.4GHz wireless transmission technology, the signal without interference ensures a private and secure connection. Range up to 984 feet (unblocked), allowing parents to move freely throughout the home and keep baby in sight Baby Soothing Music: Listening to music (max 8 pieces) for .Built-in lullabies can help parents to comfort baby fall into a sleep. Impressive Features:Temperature monitoring and alert; two way talk; optical pan and tilt; Sound Activated LED indicator; Screen-off audio-only mode; 2X digital zoom; 8 alarm levels, 8 lullabies