13cm x 19.5cm. Write-on / wipe-off, double-sided KEY STAGE 2 SUPER SCIENCE booklet and pen - heat sentitive ink hides the answers. Label up parts of the flower, water cycle, environment... When you rub the black boxes with your finger pad, the answers are revealed. They disappear again after four minutes. Materials, conductivity, mircro-organisms, adaptability, rocks, evaporation, filtration... for 8 to 11 year olds. Practise science, again and again on the go.