Echo Valley 4422R Luna-Sol LunaLite, 6-Inch by 6-Inch by 15-3/4-Inch Solar enhanced glow in the dark Concealed solar panel recharges the AA Ni-Mh battery that comes standard with each unit UV LED light supercharges the luminescent crystals in glass lamp at night amplifying glow duration and brightness Light detecting sensor in the solar panel automatically turns light on at dusk and off at dawn Do not expose to extreme temperatures and bring product inside during the winter