Black Solar Powered LED Plastic Post Cap 3.5 in X 3.5 in Includes 1aa High Powered Rechargeable Battery Fits Nominal 4 x 4 Fence or Deck Post 3.5 in w x 3.5 in x 4.1 in tall High quality solar panel Easy installation - No wiring required Long Lasting LED bulb / Rechargeable battery and hardware included