Bluebird Box House is made of insect and rot resistant premium cedar and stainless steel screws. This house features extra air vents, clean-out doors, elevated mesh floor, predator guard, fledgling skerfs, and a 1 Â½ inch entry hole. This bluebird house can be pole or flush mounted, and includes a water-based protective stain and Nature's Way Bird Products' exclusive 5 year warranty! The CWH3 Bluebird House comes with the predator guard installed for the Eastern Bluebird with hole size 1 1/2 inch. Included in the box is the predator guard for the Western or Mountain Bluebird with the hole size of 1 9/16 inch, that the consumer can change out if they are in the Western U.S.