The Model 1837 is an ideal telephone entry and access control system suited for medium to large apartment and gated community applications as well as office buildings and industrial sites.  Each 1830 Series unit allows for a Voice and Data connection over Cellular, VoIP, Internet or a POTS (Plain Old Telephone Service) connection.  The eight-line LCD display features big 1/2-inch characters for easy viewing and your personalized message appears on the screen when the system is not in use.