14, UV-treated plates with rounded corners and punched screw holes. Plates attach to the outside of the houses over the original entrance holes. 3" x 4-3/8" Conley II plates have been a great success. They help to keep out Owls from reaching in and Starlings out. Purple martins have no trouble going in or out. These were used for one season on my purple martin T-14 Polywood house. They can be used on a wooden house also. The last picture shows one has a small tear but no problem using. Great for replacing older adapter plates or installing on a new home-made house. Or, changing from a round hole or crescent hole to a Conley II style. When installing make sure the Conley II hole in plate is completely open. When installing make sure the bottom of the plate is sitting on the porch. The more starlings have to stoop to look in the less they can push. Pictures are part of the description. Conely II entrance, Purple Martin, Purple Martin house entrance hole. Cover to change the hole/entrance on a bird house for Purple Martins.