The Yankee Dipper features collapsible, mechanical perches that are weight-activated using a patented design. Small birds can perch and eat, but large birds and squirrels can cause the perches to collapse. Perches reset automatically. Its UV-stabilized polycarbonate seed tube can hold up to 5 pounds of seed, while its metal cap fits so snugly that squirrels cannot pry it off. The tube is long enough so that squirrels cannot hang down from the top and reach the seed. Its interior is properly baffled to direct seed to the 4 seed ports positioned around the tube. Metal parts have a lovely burgundy finish. 21" long, 4 3/4" diameter.