You'll be getting 52 graphics (coloured and line art) to teach the heating and cooling effects.
Illustration of Hot and Cold:
Heating and Cooling Effect:
Thin and Thick Glasses
Road Gaps and Cracked Roads
Railway Track Gaps and Bent Railway Tracks
Loose and Taut Overhead Cables
Heating and Cooling Effect on Solids, Liquids and Gases
There is another set that covers Heat Transfer:
Heat Transfer Cllpart
If you liked both, get this bundle at a discount!