Products in this family are used for over-current fault protection, and function on the basis of current flow in excess of a desired maximum causing the destruction of a conductive element within the device. They are distinguished from common fuses by one of several factors; bearing a non-supplementary classification under the UL248 standard, certification for use in hazardous or explosive environments, or a form factor other than those commonly encountered in products used for supplementary equipment protection such as those with an indication function or fusible cable links, and fuses designated for specific applications such as protection of telecommunications circuits or multimeters.