The Songbird Essentials 17-inch Green Spiral Sunflower Tube Feeder features a patented spiral design that is proven to attract more birds than a traditional feeder. This feeder measures 17 inches long, and it is constructed from heavy-duty polycarbonate materials with a green aluminum base and top to ensure durability. This spiral sunflower tube feeder features a squirrel-proof locking lid and a twist-off base for quick filling and easy cleaning. With the unique spiral-style perch that wraps around the entire feeding tube, numerous birds can feed in comfort without disturbing each other. The Songbird Essentials 17-inch Green Spiral Sunflower Tube Feeder can hold up to 1 ½ pounds of sunflower seeds, and it can accommodate up to 20 birds at a time.