This gorgeous Blue Bird house is built to Audubon specifications. Each features a 1 9/16 in. hole. The Coppertop house is fitted with a hand-crafted 12 oz. copper roof made of natural cedar. Easy to clean. High-quality, handcrafted natural cedar construction with predator guard and easy open front for cleaning. This house is ornithologically correct for the Eastern Bluebird, Mountain Bluebird and Western Bluebird. And is with all Woodlink "Audubon Series", this house is made in the USA.