Nature's Way Bird Products CWH5 Cedar Peterson Style Bluebird House Crafted from Insect and Rot Resistant Premium Cedar with a Water-Based Protective Stain Air Vents Allow for Maximum Air Ventilation Through Wall and Floor Openings Clean-Out Doors Provide Easy Access for Cleaning Entrance Hole Measures 1-3/8-Inches by 2-1/2-Inches to Keep Out Predators Pole Mount or Flush Mount Installation Options - All Included Hardware is Rust-Free