The RAK6053 lateral duct adapter is used to modify the Zoneline (AZ45 and AZ65 series) so that discharged air may be directed into a secondary room. After the RAK6053 lateral duct adapter is installed on the Zoneline chassis and case, a 44 long lateral duct (RAK601B) may be attached to either the right or left end of the RAK6053 lateral duct adapter.