308 Series Surface Mount Fuses Littelfuse 308 Series Surface Mount Fuses are surface-mountable encapsulated fuses certified as intrinsically safe components for hazardous locations. These fuses limit the energy and temperature generated during the operation. The fuse design and encapsulant are suitable for use in intrinsically safe apparatus and associated apparatus for peak voltage not exceeding 30V. Littelfuse 308 Series Surface Mount Fuses are ideal for the oil, gas, mine, chemical, pharmaceutical, and process industries.