trying to replace bulb in sentry light, this seemed to be the right one. it fit the socket, power supply seemed to be right. but amount of light put out was about equal to a candle. could hardly tell it was on. something wrong here, might not be the bulb, but there seemed to be no way to figure out exactly why this would not work. got an LED light that is terrific, characterized as a barn light. why barn, who knows. its an outdoor security light that is very bright and said to last for ever.