Test clip insulators are small sleeves that are designed to protect the person who is using the test clips from potential electrical shock, an effective yet simple way of ensuring safety. They are made in various shapes and sizes to fit over the different sorts of metal clips that are used for testing. Test clip insulators are usually made from plastic or PVC and work by preventing any conductive materials from coming onto contact with the metal clip. Without these insulators, there is a risk of both a short circuit and an electric shock.