This beautiful Bluebird house is approved by the North American Bluebird Society (NABS). Ventilation slots under the roof help regulate the temperature. The sloping roof and drainage hole keep this house dry. A clear plastic panel lets you observe the nest without disturbing it and it easily unscrews and slides out when it’s time to discard the abandoned nest.A predator guard reinforces the entrance hole. Notice the lack of a perch near the entrance to deter intruders. Made of long-lasting, durable plastic lumber. Etched plastic on the inside front panel that serves as a ladder. Includes screws for mounting. Attach this beautiful Bluebird house to a tree or post 4-8 feet above ground.