http://www.patiogardenponds.com/ If you are looking for a round flange then Achla Designs Round Flange for 4 x 4 Post, Birdhouse Post is the answer for you; this is a round flange used for mounting bird feeders and bird houses to a 4 x 4 wood post. This round flange is finished with black powder coat for the elegant finish that will surely withstand the elements.