2.25"L x 1.25" wide openings on the cage, allow small birds to access the seed tube while deterring large birds and squirrels. The center reservoir holds 1.4 quarts of mixed seed, cracked corn, or safflower seed, and a funnel at the top collar makes filling simple. This feeder has six reinforced ports with a perches The bird feeder has a steel roof to help feed stay dry. The roof locks in place, stopping squirrels from lifting it and a permanent attached, metal hanger makes it easy to suspend from a bracket or branch. The unit disassembles for cleaning.