The e-string is the violins highest and the contrabass lowest string. Today it is made of pure steel or of steel-core string. The outer layer can be gold as is the case with Pirastros Obligato or Oliv strings, Tomastik-Infeld strings are made of tin and the Larsen Company uses chrome steel or aluminum to coat the steel core of the string. Originally sheep gut strings were used. Today these strings are used mainly for historical performances. A modern violinist might be surprised at the effect of these strings which have a surprising sound range that is quite nuanced. Their disadvantage is very limited durability and great sensitivity to temperature and moisture fluctuations.