The light is powered by solar energy through solar panel. The solar panel converts sunlight into electric energy and then charges built-in AANi-cD rechargeable batteries during daytime. A light sensor turns on the light automatically at night. The light can work up to 8 hours at night after a full sunny day charging. The light doesnt only light up and decorate your house and garden, but also saves electric energy. Remark: The lifetime of LED lamp is over100, 000 hours , you never need to change it. Stainless material Unit Size: Height(42cm)*Diameter(13cm)