This is a Duro-Test bulb from Mexico, also sold under the brand name Duro-Mex. These were designed for long life, and were meant for business and industrial applications. They would last much longer than your average incandescent bulb. Another common use that they wad was on traffic signals, back in the days when there were still no LED lights available. The Spanish on the packaging says "The best lamps in the world."
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