Pico 5557PT 8" Universal 20 Gauge Fusible Link - Black 1 per Package - Fusible Links "Open" Circuit when overload occurs preventing damage to vehicle wire harness. When too much current is run through the Fusible Link the internal stranded bare copper wire will burn up and blow the circuit, while the Hypalon Rubber insulation will contain any spark or flame that may occur. When this occurs the Fusible Link will need to be replaced much like a normal fuse.