This great new product will alert you if a car or person passes by the transmitter. Simply place the transmitter near the entrance to your driveway and any anything passing by the transmitter will cause the receiver to sound a pleasant 80 dB alarm. The Driveway Patrol has a whopping 400-foot range and is battery operated, making it easily portable, allowing you to use it to “guard” almost anything you can imagine. Businesses owners can monitor a back entrance to their store. Parents can monitor their home for children that may sneak out at night! Requires one 9-volt and three “C” size batteries, not included.