Comprising of  heavily plated brass strips mounted on polished hardwood base, Constantan resistance wire 24 SWG  stretched along the top of metre scale,in centimetres and millimetres. clamped to stout plated brass terminating plates designed to ensure that the connections are made exactly at the ends of the scale. Terminal are provided to reduce unwanted resistance to a minimum and the gaps are closed by removable plated brass strips which are held in position by the terminals. Supplied with Pencil jockey.