Keep in mind that they only fit over standard 4x4 posts, which typically measure slightly smaller than exactly 4 inches. These Solar-Powered Fence Post Caps Add A Flickering Effect Even In Bad ...

Note that wood fence posts might have nominal sizes that don't reflect their actual dimensions. For example, 4x4 posts will actually measure to be 3 ⅝ by 3 ⅝ inches, and post caps, like these ...