Fits Standard Posts of: 4 in. x 4 in. (actual size 3.5 in. x 3.5 in., 89 mm x 89 mm) and 4.5 in. x 4.5 in. (actual size 4 in. x 4 in.). See images. Some sanding or cutting may be required depending on post type. Most do NOT need modification though. Dimension L x W x H: 5.6 in. x 5.6 in. x 3 in. Colors: BLACK, WHITE, PEWTER, GREEN, RED, WALNUT.