Prevent large birds and squirrels from eating all your bird food! You save money on seed when you use a Yankee Squirrel Proof Bird Feeder. The weight sensitive perches encourage smaller songbirds to eat, while preventing all squirrels from feeding. Each perch is individually sprung and calibrated to collapse when approximately 2oz or more rests on the perch. The heavy metal cap fits snugly on the tube to prevent squirrels from lifting it to reach the seed. The long, clear feeder tube makes the seed visible to the birds, a proven advantage. Made of UV stabilized polycarbonate, it ensures long lasting durability. Its length and girth are designed to prevent squirrels from reaching the seed ports. An internal baffle design keeps seed flowing freely to the ports. Metal cap and base are powder coated.