ETL Number is the Manufacturer Right to Mark Number! This is the actual product owner/producer who originally used the ETL lab. Each Intertek Lab has it's own reports that do not use this number but Intertek Cortland NY USA has the ETL manufacturing plant(s) that use that right to mark. You will note that 4 agencies have the NRTL rights to mark in US/CAN without question by Federal and Treaty rights. UL that investigates worldwide but headquarters in Northbrook IL, CSA Worldwide, Toronto CAN, ETL/Interek Worldwide, Cortland NY, VDE Worldwide, Germany. UL and CSA generally have electronically search-able databases. Intertek easily could have told you the factory if you reached the correct person which is easier than UL and on par with CSA.