State-of-the-art Chamberlain Wireless Motion Alert System alerts you the moment someone enters your property. You'll always have advance notice that you have visitors. System features compact, discreet adjustable infrared motion sensor that installs on garage, mailbox, fence post...nearly anywhere! When activated by the movement of people or vehicles, it transmit signals up to a half mile to the receiver, and detect motion up to 30 feet away! Perfect for private roads, long driveways or an extra sense of security around garages, decks, patios, businesses, storefronts, entryways and outbuildings. U.S.A.