Fuse holders are devices for containing, protecting and mounting fuses. Fuse holders come in two basic types, open or fully enclosed. Open fuse holder types are fuse clips, fuse blocks, socket and plug-on cap varieties. The fully enclosed variety may use a fuse carrier that is inserted into a holder or have other means to fully enclose the fuse.
A fuse is a replaceable circuit protection device that provides protection to both the equipment and the equipment operator in the event of a circuit overload. The traditional fuse mainly consists of two parts of a tube body, of which both ends have metal connecting terminals, and metal melts in the tube body. The majority of fuses are cylinder-shaped, namely cartridge construction.