This ingenious bird feeder allows you to watch birds from indoors at very close quarters without disturbing them. Attaching to a casement window in seconds, the feeder has a back wall that acts as a one-way mirror, so as birds feed, they are unaware that they are being watched so closely. In fact, the feeder makes an ideal cat toy, providing cats with hours of enjoyment as they watch birds without being able to harm them. The top of the feeder flips up, allowing bird seed to be poured in; and as the birds eat, more feed spills out onto the feeding platform, ensuring a continuous supply of food. Simply attach the feeder to the non-moving part of the window, using your choice of suction cups or velcro (both included), and then fill it by opening the casement window. 15 3?4" H x 9 1?2" W x 5 1?4" D. (2.25 lbs.)