Twisted pair cable has two individually insulated conductors (wires) that are twisted together. Such construction is beneficial for signal transmission as it minimizes electromagnetic interference from external sources. The insulation on different wires is color-coded. In this photograph each conductor is composed of a bundle of small-gauge wires and is called a stranded wire. Each thin wire in a strand is made of copper plated with nickel. Copper has a high electrical conductivity while nickel provides high thermal stability and corrosion resistance.