Easy InstallationEach package contains 2 bases (4x4 wooden post and 4x4 vinyl post) and screws. Choose the appropriate base size and place it on the corresponding post, then screw the two screws into the post through the small holes on both sides of the base. The solar fence post cap light is charged in sunlight for 6-8 hours during the day and automatically turns on for 10-12 hours at night Fit for post sizeOur 4x4 solar deck post cap lights come in various sizes. It is suitable for 4x4 wooden post, 4x4 vinyl post. It can illuminating fences, decks, mailboxes, making them a versatile and stylish addition to any outdoor space