Used two out of 6 and one burned out within 24 hours. The other one was used a lot in hall lighting without any problems. I used them in new lights. I used a regular light bulb and replaced a blown bulb in a new fixture 3-4 feet from the cooking area of my kitchen. This light is on almost all the time so I need a reliable lightbulb and this wasn't it. The area and type of fixture could be too hot for this type of lamp, I don't know. Since the frosted mount doesn't allow the filament, I probably shouldn't have used it.