Learning Resources Primary Science Jumbo Test Tubes with Stand. These oversized and colourful science tools are ideal for little hands to grip while supporting hands-on observation and investigations. The jumbo test tubes feature calibration marks of 25, 50, 75 and 100 ml to encourage experimenting with volume. Made of sturdy plastic, the tubes are safe to be used with liquids from -12 to 93 degrees Celsius. The brightly coloured screw-on lids are wipe clean to enable labelling for different activities. Set comes complete with useful plastic stand for storage, 14 cm width. Test tubes measure 15 cm height. Suitable for ages 3 years and above.