This recycled one and our wood ultimate bluebird house is the most deluxe functional bird-friendly Bluebird House on the market today. It is approved by the North American Bluebird Society. Side doors are etched with ‘VIEW” AND “CLEAN”. Behind the VIEW door is a clear plexy panel that holds the nest secure, while you view the eggs or babies in the house. The raised screen on the bottom of the house protects the nest from blowfly infestation. If blowflys get into the nest, they will drop to the floor of the bird house and not be able to get back to the nest. 1-1/2? Entrance hole includes predator guard and copper portal. Blue roof with a taupe base.