These outdoor fixtures are made as all one piece, so there is no room for small adjustments.  We had this light installed by a skilled electrician.  The plate is absolutely square, but the lantern is crooked.  There's no way to adjust without risking breaking it because it is all one molded piece.  The light did not include the brackets, so the electrician had to use brackets from the existing fixtures.  No big deal, but another indication of cheap.  You get what you pay for.  I'm disappointed and do not recommend these light fixtures.