Security camera system with 7 inch quad monitor for truck-trailer Security camera system with 7 inch quad monitor for truck-trailer This system is mainly ... ( actually, you can choose 1 to 4 cameras in this system ) , 1 curly cable, 2 cables ( waterproof, for connecting from the ... cameras to the monitor ) and 2 brackets for large plugs. The cameras can be installed on the front, back ...