From Droll Yankees, these perch rings allow you to give your birds choice as to how they position themselves at the feeder port. Some birds are happy to use the feeder's perch bar, but other species may struggle with this, or prefer to position themselves head-on, keeping a wary eye out for predators. The polycarbonate rings easily clip on to the feeder perch & can be removed just as quickly so you can see which your birds prefer. Pack of 6 can be used to improve birds' comfort & safety in your garden.