The Whipper features four seed ports with individual weight sensitive perches. The curved perch positioning encourages cardinals and small songbirds to eat, but prevents squirrels from feeding. Each perch is individually sprung and calibrated for birds up to the weight of a cardinal (approx. 2 oz.). Length and girth of the feeder are specific to repelling squirrels. The heavy metal cap is constructed to prevent squirrels from raising the cap and reaching the seed inside. An internal baffle design delivers the seed to the ports. The 4-3/4 inch x 21 inch clear feeder tube is made of UV stabilized polycarbonate for long lasting durability without yellowing. The metal cap and feeder base are powder coated a stunning Evening Blue. The Whipper hangs from a looped stainless steel wire that reduces motion that would spill seed. Add a Locking Chain to secure it against falls. Components made in the U.S A. and in China. Lifetime Warranty against squirrel damage.