Learning Resources Rainbow Reactions Preschool Science Lab. Explore the world of science and chemistry through doing colourful experiments using a durable lab set made especially for young children. Young scientists use the sets test tubes, centre flask, colour lenses, and fine motor droppers to do the fun experiments featured in the included experiment guide. The pieces fit inside the rainbow tray for easy storage. Features multilingual packaging and guide. Tray measures 21.5 cm L x 20cm. 14 Piece Set (Ages 4+)