It's a track...with a ball in it. What makes it different? You can arrange it into any configuration you want! Or, better yet, you can keep your cat from getting bored with the same old thing by changing it up every now and then. Each piece twist-locks together with any other piece, making the possibilities endless. Heck, buy 10 sets and transform it from a track to a highway that keeps your cat entertained for hours and encouraged exercise for a happier, healthier cat.