At lastthe ring to top them all This Fisher-Price Rock-a-Stack toy, made from plant-based materials*, offers classic stacking fun for babies It features a wibbly-wobby rocker base and 5 colorful rings for little hands to grasp and stack Stacking helps baby develop hand-eye coordination and introduces them to the concept of relative size as they learn to sort and stack from biggest to smallest (*Toy made from a minimum of 90% ethanol extracted from sugar cane)