Wheel Cylinder is a direct fit for the following:

2005-2008 Chevrolet Silverado 1500
2007 Chevrolet Silverado 1500 Classic
2005-2006 Chevrolet Silverado 1500 HD
2007 Chevrolet Silverado 1500 HD Classic
2005-2008 Chevrolet Silverado 2500 HD
2007 Chevrolet Silverado 2500 HD Classic
2005-2006 Chevrolet Silverado 3500
2007 Chevrolet Silverado 3500 Classic
2007-2008 Chevrolet Silverado 3500 HD
2005-2008 GMC Sierra 1500
2007 GMC Sierra 1500 Classic
2005-2006 GMC Sierra 1500 HD
2007 GMC Sierra 1500 HD Classic
2005-2008 GMC Sierra 2500 HD
2007 GMC Sierra 2500 HD Classic
2005-2006 GMC Sierra 3500
2007 GMC Sierra 3500 Classic
2007-2008 GMC Sierra 3500 HD

Genuine GM Part Number: 19133370