Brome 1024 Squirrel Buster Plus Wild Bird Feeder with Cardinal Perch Ring. This posigrip ring system has been specifically designed to attract cardinals. These perennial favorites have two very distinct features: small necks and big feet. They prefer gripping a thicktextured perch and facing their food source directly. Cardinals dislike turning their heads to feed. The Squirrel Buster Plus Cardinal Ring perch system allows them to eat facing the seed while providing a secure and comfortable perch. These cardinalfriendly feeding features combined with a bush level location make Squirrel Buster Plus very inviting to cardinals. The seed ports close automatically when a squirrel climbs onto the feeder. Birdwatch America's Best New Product Award. Seed capacity: 3 quarts.