An example of a combination product would the halo bone fracture apparatus. Since this apparatus has wires that will keep the halos in place it is a combination of multiple parts. This device is classified as a class II device, because the wires will have to puncture the skin. The medical wires used are of a biologically acceptable material, so as to not produce a immune response and they have special coatings to prevent inflammation or patient immune response. The outside metal component or the halo is what the wires bind to and they help immobilize the fractured bone of the patient. To go through FDA protocol, the wire must first go through clinical testing to show that the coatings used provide a safe environment for patient and do not elicit any negative health effects. They would have to conduct animal testing first to provide relative lab results.