Holds 5 pounds of seed. Motor driven, weight activated perch ring flips squirrels off when weight is applied. The weight activated feeding perch is v-calibrated to react to a squirrels weight. Birds will not set it off, not even larger species like Woodpeckers and Cardinals. However, the second a squirrel hops on to the perch, the motor is triggered and the feeder begins spinning, taking the squirrel for a whirl before it loses its grip and is thrown gently from the perch. The seed tube is generous in height, making it impossible for squirrels to hang down from the top and reach the seed The four feeding ports are easily accessible via the perch ring The heavy metal cap fits snugly on the tube to prevent squirrels from lifting it to reach the seed.