BIRUGEAR Plastic White Square Fence Post Cap Solar Powered LED Light - (Set of 4) Sun Powered. No Wiring. On/Off switch. Ultra Bright LED. Powered by the sun. Fast & easy install rechargeable Ni-Cd AA battery included. Energy, electrical saving Ideal for areas where conventional electrical supply is not available One High output long lasting ultra-bright LED bulb. More expensive ultra-highly sensitive solar panel usually seen on calculators is used Automatic dusk-to-dawn operation, On/off manual over-ride switch. Product size 6"x6"x4.5", inner post mount dimension 5"x5"