The principal shapes of insulator are shown. Vertical-loaded strings of cap-and pin discs are known, in England, as 'suspension sets' and when horizontal loaded as 'tension sets'. For horizontal duty the shape is usually modified towards lesser convolution. 'Pedestal posts' are either assembled from single units of metal and porcelain, bolted together, or in the 'polyped' form. Sub-assemblies using continuous metal parts and embodying several units of metal and porcelain are bolted together. The 'solid-core' post is of continuous porcelain with metal fittings, like the 'longrod' and 'motor' but of much larger diameter. Its appearance is much the same as that of the 'multiple cone' which, as shown, comprises both porcelain and cement.