15 dome acts as a rain guard. UV stabilized polycarbonate prevents yellowing. Safety lock hook secures feeder. Articulating design - weight of a squirrel displaces feeder hung beneath. Effective over any hanging feeder. Squirrel guard green. Made in the usa. Covered by the droll yankees lifetime warranty.Size is 15 Inch. Dimensions are 15 X 15 X 12.75 UPC Code = 021964103156