Australiana LEAVES stacker with Koala topper.Wooden Australiana LEAVES stacker with Koala topper. This fun stacker has been designed to assist with developing your child's imagination and hand eye coordination while being a fantastic way to teach them about size variations, colours, stacking, sorting, numbers and much more. Complete stacker is approx: 22cmH x 12. 5 cmW Ring Stackers are made out of pine. Koala toppers are made out of 30mm plywood. They are hand painted with non toxic acrylic