Used in older-model cars, glass tube fuses today are found primarily in automotive accessory applications. There are two basic types of glass fuses available: fast-acting or time-delay. Any replacement fuse must match the one it’s replacing. In general, fast-acting fuses are a single strand of wire or strip of metal. Time-delay fuses usually have a coiled wire, a thick element wrapped in wire, or a spring. Most electronic fuses will have the voltage and amp rating stamped on the end cap. The type of fuse can generally be visually identified.