Viking AES-2000F 75 Entry System | 16 positions | Back-lit display with 1/2″ tall characters | Non-volatile digital voice announcer | Factory configured to handle 75 apartments (expandable to 525 apartments using ERAM-4M expansion kits) | Non-volatile data memory for names, phone numbers, and access codes | Volume control | TTY jack for connection to personal teletypewriter (TTY) | Postal lock switch input | Available in surface mount (AES-2000F) | Keyless entry capability