Nuvo Iron Solar Fence Post Light (For 5.5" X 5.5" Posts) Spc27 + Post Cap/adapter Spc24 (Copper Plated) Post Light FITS Standard 4" x 4" posts (3.5" x 3.5"actual post size) Adapter Cap FITS Standard 6" x 6" posts (5.5"x5.5" actual post size) Adapter Cap fits Model: SPC27, SPC22 Easy to install (includes 2 wood screws), Solar powered LED light, Up to 8 hours on a full charge