This hummingbird feeder attaches with a suction cup bracket to an outdoor window. They are so simple to assemble. Just fill an empty plastic or glass 16-20 oz. Pepsi product soda bottle with nectar (sugar and water), twist on the feeding base, and attach to a window. Now you can lure these illusive little birds closer and enjoy the view. Soda Bottle Hummingbird feeders make wonderful gifts for Nature lovers and are an especially nice way to dress up the backyard. Soda Bottle bird feeders not included. MADE IN USA