Copper-Plated Solar Post Cap Light Decorative Solar Light for 4x4 Posts (Inside Dimensions measure 3-5/8" x 3-5/8") Brightens up its immediate surroundings with warm ambient light An outdoor solar light made especially for 4x4 posts. Inside dimensions of 3-5/8" x 3-5/8" Features a built-in solar panel that powers its 1 Watt LED Runs for 6-8 hours, under a full charge