Learning Resources Starter Science Measuring Flasks. Children can measure and mix liquids just like real scientists with these realistic flasks made especially for young scientists. Each is made from transparent, durable plastic, has a stopper that fits snugly, and nests neatly in the included stand. There are 3 flasks (50, 100, and 250ml) which have large, easy-to-read measurements engraved and printed on the sides. Includes 3 flasks with stoppers, stand, and a cleaning brush. Features multilingual packaging and guide. Largest flask measures 7.5cm L x 11cm H. 8 Piece Set (Ages 3+)