Chunky, durable test tubes put serious science safely within reach for young students! Encourages inquiry-based investigation and hands-on observation. Supports serious science experiments - plastic tubes are safe at temperatures from 10 degrees -200 degrees F and feature calibration marks (25, 50, 75 and 100 ml)Includes 6 test tubes, different colored lids (to track experiments), sturdy rack and Activity Guide. Hand wash. Tubes measure 6"H x 1.5" in diameter. Grades PreK+.