Help baby build new discoveries with the Baby Einstein Ocean Explorers Opus’s Stack Stream Sensory Stacking Cups, a 5-piece set of nesting cups and accessories that engage baby in sensory play and promote cause and effect and fine motor skills. Designed to let baby explore as they stack, stream, and pour, each of the 4 ocean-themed cups is large and textured for baby to easily grasp and play. Squeeze in some cause-and-effect fun with the purple clamshell water squirter, or delight in watching Opus the Octopus from Baby Einstein Ocean Explorers change color in warm water! Perfect for water play or floor play.