Rangs Japan Flat Ball - Blue and Yellow It's not made of rubber, but it's hard. It has a spring and a suction cup inside, and when you squeeze it, it pops back after a while. I've only used it a few times indoors, so I don't think there are any noticeable scratches or stains. I will flatten it and try to secure it so it doesn't return to its round shape during shipping, and then I will send it. Thank you.