Quantum DXi8500, one to four total Array Module(s) and/or Expansion Module(s), Field Upgrade, Onsite

This is a Quantum DXi8500, one to four total Array Module(s) and/or Expansion Module(s), Field Upgrade, Onsite Installation, zone 1 Required. Order this item for professional onsite installation of up to four Array and/or Expansion Modules added after initial system installation.. Quantum DXi8500, one to four total Array Module(s) and/or Expansion Module(s), Field Upgrade, Onsite SDY85-NC4D-0001 SDY85-NC4D-0001