Specifications: INCREASES CONCENTRATION. Equipped with 4 different color balls, the tower of tracks by pet stages simulates your cats senses and excites their mind as they work to bat at every ball. SUPERIOR DESIGN: With three layers design, the cat toy supports to be detachable and assembled, easy to clean after use. And there are anti-slip mats on the bottom of the toy for avoiding slipping. BUILT-IN TRACKS: With a built-in track, the cat can move the ball inside the track and move it along the track ,it can give your pets more fun Bar across top prevents your cat's head from getting stuck, non-skid pads at bottom ensure cat toy doesn't slip. Bright color, very interesting and intellectual toys, entertain your cats and protect your furniture from clawing.