Tail Light Wiring Harness is a direct fit for the following:

2003-2007 Chevrolet Silverado 1500
2003-2006 Chevrolet Silverado 1500 HD
2003-2007 Chevrolet Silverado 2500 HD
2003-2007 Chevrolet Silverado 3500

Genuine GM Part Number: 16531402