Captured inside the Sun and Moon Jars are a highly efficient solar cell, a rechargeable battery and a low energy LED. When the jar is placed in direct sunlight the solar cell creates an electrical current that charges the battery over a few hours. This energy is then used at night to power the LED lamp inside the jar. The light is diffused by the frosted jar and give the appearance of sunlight emitting from the Sun or a Cool Moon Glow.