3 year update: We have used about 12 out of 25 bulbs in 2 salt lanterns in 3 years. Salt lanterns 24 hours a day, only off when changing the lightbulb. As mentioned below, after screwing it back in (turn it off), wipe the bulb with alcohol, a tissue if you have one, or a cotton swab quickly dampened with alcohol. . Arrived as advertised, only one delivered so far, no problems. The 4 pack in Brick and Mortar costs 3.99, worth the risk to try. Previous locally bought C7s lasted 9-10 months, we…