Leak-proof design is a Droll Yankees Guarantee! 6 oz. capacity. Classic window hummingbird feeder lets hummers come close for spectacular view. Droll Yankee Industry Leading Features: *2 feeding ports are positioned for unobstructed view. *Perching rim provides hummers with resting place. *Suction cup bar is an easy off design that holds feeder securely to the window. *Easy-fill cap and cleaning cover.