An insulator is a material that does not conduct electrical current. Insulating materials include paper, plastic, rubber, glass and air. Vacuum is also an insulator, but is not actually a material. Most electrical conductors are covered by insulation. Magnet wire is coated with an extremely thin layer of insulation so that more turns or larger wire may be used in the winding of transformers etc. Insulators are generally rated at hundreds of volts, but some that are used in power distribution are rated as high as hundreds of thousands of volts. Insulators support and/or keep electrical conductors from making unintended contact with each other
