Easily close the starling resistant entrance doors in your existing S&K purple martin house with these S&K Crescent Door Plugs. This set of 16 plugs easily covers the starling resistant openings on your existing S&K Purple Martin Barn house, allowing you to leave it up during the winter without fear of starlings or sparrows overtaking it. The package also provides enough covers for two of the S&K Farm and Home or S&K Great Eight martin house, each with 8 rooms. The bottom tabs and top clip on each unit keep them securely affixed to your martin house, and their plastic construction blends with the shelter. The crescent shape of these units fully covers the starling resistant entries on the home, and are simple to remove when it is time for your martins to return. Stop starlings and sparrows from overtaking your S&K Purple Martin Barn, S&K Farm and Home, or S&K Great Eight martin house in the winter with these Crescent Door Plugs. Made in the USA.