The five rods have depression on the ends to hold wax. To demonstrate the difference in thermal conductivity of different metals. Consists of five metal rods stainless steel, brass, copper, iron and aluminum connected to a center metal, brass, hub which is mounted on a rod with wooden handle. When the center hub is heated, heat is conducted through the rods and conductivity of heat can be ascertained by the melting of wax. Measurements are approximate.