-The Whipper features four seed ports with individual weight sensitive perches
-Curved perch design encourages cardinals and small songbirds to eat, but prevents squirrels from feeding.
-Each perch is individually sprung and calibrated to collapse when approximately 2 oz. or more rests on the perch
-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" x 21" 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

Hungry birds will adapt as best they can to the conditions in order to survive and larger birds will sometimes hang onto the collapsed perch and continue to feed. It is uncomfortable for them and difficult so it discourages them but might not be the ultimate preventative.