Review on Sunlite 100W MV100/DX/MOG H38 Mercury Vapor Lamp, Mogul Base (E39), ED23, 8000 Hour Life, 4200 Lumen, Coated White Finish - 1 Count (Pack of 1) by Alex Montgomery

Bought three - first burned out after 2 months, other 2 not lit - junk - avoid. They were purchased to be used in a colonial post top light fixture - similar to those used by residential utility companies. I worked in a public utility and 100 watt mercury lamps lasted 3 years and then slowly dimmed. End of life is when they no longer emit 4,000 lumens of light (so-called foot candles), typically within 5 years. I took a lightbulb from the local power supply and the post top lightbulb works fine now.