The Fisher & Western 64077 is a discontinued 12-pin relay-style harness kit, specifically for 2003-2006 Chevy and GMC trucks with HB3 and HB4 headlights and daytime running lights. This complete kit provides the necessary truck-side wiring to connect a snowplow, including the control harness, headlight harness, and hardware bags. It is a crucial, though no longer produced, OEM part for integrating a plow onto compatible truck models.