Solar Tiffany-style California Grape 4x4 post caps bring matchless stained-glass beauty to your deck, transforming it from a project to a work of art. These solar post caps lights brighten your deck, fence or rail day and night—without wiring or electricity. By day, see the beauty of stained glass in your outdoors. By night, enhance your setting with a welcoming glow. Inside dimensions measure 3-5/8-by-3-5/8-Inch, for post measuring 3-1/2-by-3-1/2-Inch. Attach by applying exterior caulk to the under-side of the post cap before placing it on the post.Solar Tiffany-style Sunflower 4x4 post capsTreated Wood BaseGlass topFits 4X4 nominal post measuring 3.5"X3.5"Protects wood posts from the elements