Simply sit the jars on your windowsill during the day, then when it gets dark they automatically turn themselves on and glow with the day's sunshine. Made with a traditional Mason jar and high tech energy efficient lighting! Captured inside the jar are a highly efficient solar cell, rechargeable battery and low energy LED lamps. When the jar is placed in 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 three LED lamps inside the jar.