ETL is the abbreviation of Electrical Testing Laboratories in the United States. ETL laboratory was founded by American inventor Edison in 1896 and enjoys a high reputation in the United States and the world. Like UL and CSA, ETL can test and issue ETL certification marks according to UL standards or American national standards, and can also test and issue composite certification marks according to UL standards or American national standards and CSA standards or Canadian standards. "us" in the bottom right means it's for the US, "c" in the bottom left means it's for Canada, and having both "us" and "c" means it's for both countries.
What is NRTL:
A nationally recognized NRTL is an independent laboratory accredited by the U.S. Occupational Safety and Health Council (OSHA) to test products against the requirements of applicable product safety standards such as those developed by UL and other standards-setting bodies .
