C&S Bluebird Feeders are designed exclusively for use with C&S Bluebird Nuggets. Simply place a handful on top of or outside of your feeder to make it easier for the bluebirds to find the food. Once they have found it, they will quickly venture inside the feeder to feast on this high energy food source. The clear Plexiglass sides allow for easy viewing. 11.875Â x 9Â x 8Â high.