Area code and exchange code is assigned to every constituent of city in the United States. The area and exchange codes of the telephone can be used to find information about a region. Area code 415 and exchange code 795 is assigned to San Francisco. The latitude and longitude corresponding to 37.79028 and -122.40622 can be used to find an area on the map. Halo Wirelessoperates most of the land lines in United States.