Description Economically and accurately demonstrates the coefficient of thermal expansion of different metals with an easy to read scale. This apparatus contains 3 removable rods (aluminum, brass & steel), each measuring 7.25" / 18.4cm in length. When heated by a candle (votives recommended, not included), the metals will expand at different rates as demonstrated by the pointers to which they are attached. The rods can be removed and re-positioned on different pointers. This apparatus is easy to adjust and quick to zero. Includes heat plate and candle holder / wax trough. Instructions included. Specifications Dimensions (lxwxh): 9.25" x 3.25" x 11" / 23.5cm x 8.25cm x 28cm Weight: 2 lbs.