Cedar, Bluebird Viewing House, Also Includes A Side Viewing Window To Watch The Hatchlings While Keeping Them Safe, Features Maximum Ventilation, Elevated Mesh Base To Manage Blowflies, Predator Guards & Fledgling Skerfs, The Naturally Insect & Rot Resistant Cedar Has A Water Based Preservative To Maintain Color Longer & Hinder Mold & Mildew Growth, All Hardware Is Rust Free, Approved By North American Bluebird Society By Meeting Or Exceeding Their Standards, Comes With A 5 Year Warranty.