A:AnswerYes, you can add two more cameras identical to the two provided in the set, as those are the only ones compatible with this system (from what I understand).
A:AnswerFrom what I understand, only the specific cameras that are included with this system are compatible. At one time, cameras were available for purchase separately if needed.
A:AnswerThe camera does work through a window, but it depends on lighting; you may get a reflection off the glass. It will not work at night because of the reflection. The image quality is very good, I would guess you could clearly see a person at up to 50 feet or so.
