Chunky, durable test tubes put science safely within reach for young students. Plastic tubes are safe at temperatures from 10°-200°F and feature calibration marks at 25, 50, 70 and 100ml. Includes 6 tubes, each measuring 6" high and 1-1/2" in diameter, with different colored lids to aid in tracking experiments. Comes with a sturdy rack and an activity guide. For ages Pre-K and up.