Bought to replace incandescent bulbs in a pair of flashlights and Coleman's emergency light. The difference in the amount of light emitted by these lamps is enormous. My flashlights have gone from being normal or downright miserable to light-producing monsters. Replacing a lightbulb is no different than replacing a traditional lightbulb. Just remove the old one and insert the new one and you're done. In time I will replace all the incandescent bulbs with them, but they are not cheap. . . .