This new, improved student calorimeter features a specially insulated outer wall that makes the device five times more sensitive than conventional calorimeters by minimizing heat loss. The inner vessel is made of aluminum and surrounded by a layer of styrofoam insulation. The entire device is enclosed in a protective case of plastic. The Calorimeter Resistor will give you outstanding accuracy and remarkable results when used with the Calorimeter. Simply place the resistor in the calorimeter, hook it up to a power supply (not included) and measure the quanitity of volts and amperes going through it. A thermometer is required, but not included.