Breathable Oxford Cloth + Plastic. Your cat won't overheat because of the hammock breathability. In winter, you can add a mattress on this cat perch to keep your cat cozy. Industrial strength suction cups hold up to an amazing 30-40 pounds. Your cat could jump in and jump out of this resting perch, which is another kind of exercise, keeping your cat fit. Installs in seconds to glass windows or doors, please press hard on the suction cups and apply to clean glass surface. Cover easily comes off and can easily be cleaned by HAND WASHING.