Some of the LED Lights on MyLEDLightingGuide are ETL Listed. Others are UL Listed. What's the difference? Both testing companies are based here in the USA and are regulated by federal government. Both testing facilities are internationally recognized world-class operations. And most LED manufacturers submit their products to one or both of the testing facilities so that they can proudly display the certification associated with a successfully tested product. Click here to get a detailed explanation of the difference from Intertek, the facility responsible for ETL testing.