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 feeders 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 and can be removed just as quickly so you can see which your birds prefer if you have droll yankees lifetime or a6 range seed feeders th