JW Pet Spring String Cat Toy is a bouncing action toy that will stimulate your cat's feline instincts to pounce and play. This unique design allows the Spring String to attach to any style of doorknob, transforming your door into a fun, interactive toy in seconds! A furry, feathered mouse dangles on a bungee cord from the doorknob attachment at the perfect height to entice curious cats for hours of play!