This Piece started as wood from a dock . The curved areas were where the wood fit around a support pole . I have applied a copper metallic finish . The opening has been routered with a 1/4 inch round over bit . The groove in the back is 4 3/4 inches by 4 3/4 inches square and is 5/16 inch deep . The frame is approximately 10 1/2 inches wide , 13 inches high and 1 1/2 inches thick .