The 1837 90 Series stores up to 3000 phone numbers and 8000 device codes and can be expanded to control up to 48 wired access points with optional Tracker Expansion boards (up to 24 wirelessly). The 90 Series housing offers a streamlined look, has enhanced locking and weather sealing and provides easy internal installation of optional components such as a card reader, LCD heater and TCP/IP adapter for a direct internet connection. The 1837 is still available in the original 80 Series (surface and flush mount) housings, click the button below to view the 80 Series product page.