The patented Brome Bird Care Direct Squirrel Buster technology is truly squirrel proof. Thousands of delighted bird lovers have confirmed it. Openings in the wire shroud align with seed ports and provide birds access to the seed. When a squirrel climbs onto the feeder, its weight automatically forces the shroud down, closing access to the seed ports. Red and Gray Squirrels are foiled but not harmed in any way. Holds approximately 2.5 lbs. of seed. Patented Seed Tube Ventilation SystemTM:Transparent seed tubes are like greenhouses, they trap solar energy. Traditional seed tube cover designs block the escape of heated air. The patented Seed Tube Ventilation System in Squirrel Buster Classic permits humidity and warm air to escape through waterproof vents at the top of the feeder. The escaping air is replaced with fresh air entering the seed ports and openings on the bottom of the seed tube. The seed remains fresher and attracts more birds. Perches are removable: Squirrel Buster Classic can be converted into a clinging feeder only, by removing the perches. The absence of perches will help deter large perching birds such as Grackles and Doves from using the feeder. Squirrel Buster Classic Factory Warranty: Squirrel Buster Classic is guaranteed to be free of material or manufacturing defects and against squirrel damage for a period of 24 months from the date of purchase. Brome Bird Care's sole responsibility will be to repair or replace a defective or damaged product. All warranty claims must be made by calling Brome Bird Care customer service at 1-800-856-5685.