Leak-proof design of this window hummingbird feeder is a Droll Yankees guarantee. Feeder rim serves as a perch. Heavy-duty suction cups secure the feeder bar on a window, and the feeder attaches to the bar for easy removal. Just lift the feeder off the suction cup bar, turn the clear cap a quarter of a turn counter-clockwise, and lift the cap off. The nectar recipe is engraved on the rear of the red rim. UV-stabilized, impact-resistant polycarbonate plastic. Includes nectar guard tips and a small cleaning brush. Dishwasher safe. Capacity: 6 oz. Dimensions: 6" W x 5-1/2" D x 2" H. By Droll Yankees.