Great way to introduce science and working scientifically to young pupils.Chunky durable test tubes put serious science safely within reach for young students. Plastic tubes are safe at temperatures from 10° - 200°F (-12° - 93°C) and feature calibration marks (25 50 75 and 100mL).Test tubes feature different coloured lids. Sturdy rack and activity guide included. Tubes measure H150 x W30mm. Ideal for measuring water rain in Key Stages 1 and 2.