Calorimeter Cups - Pair. Outer cup 75x100mm DxH, with styrene foam insulation pad in the bottom of the cup to support and centralise a small calorimeter cup 50x75mm DxH. The air space between the two cups is the insulation medium. The mouths of the two cups are level so that a single plastic lid engages and holds both cups aligned and carries a stirrer that can operate inside the smaller cup. A hole is provided in the centre of the lid to permit a thermometer to be inserted. The stirrer operates in a vertical action without touching the thermometer.