Squirrel Blocker Select is the best sunflower bird feeder in the field. Three years of field testing made this squirrel proof. The open flow through bottom insures no seed collects to attract hairy hangers on that drive birds away. Dimensions 5.25 x 5.25 x 17.25 inches Capacity 1.5 pounds. More than a dozen birds can perch and feed from anywhere on the Squirrel-Blocker fencing. The entire tube dispenses seed, yet squirrel paws and noses cannot reach inside to the seed source! Stainless steel mesh tube keeps seed aerated and fresh. Fill with black oil sunflower seed. Duncraft's Lifetime Guarantee.