Unity automotive has over 50 years of experience manufacturing parts in the aftermarket automotive industry. The company offers superior quality, specializing in making rock solid auto parts that withstand the test of time. With a true understanding of their marketplace they have become the industry leader in innovation of aftermarket suspension. Unity automotive delivers top of the line quality suspension parts made to insure a trouble-free installation and long-lasting reliability. The Replacement Shock absorber line offers a twin tube gas charged shock to be used as a direct replacement for your failing OE shocks. We offer our shock absorbers in sets and bundles, providing an easier solution for your vehicle?s suspension at the lowest prices. The kit includes 2 Front and 2 Rear Nitrogen Gas Charged Shock Absorbers. This Product Fits: 2001-2006 Silverado 1500 HD, 1999-2004 Silverado 2500 4WD, 2005-2008 Silverado 2500, 2001-2010 Silverado 2500 HD,2001-2009 Silverado 3500, 2007-2010 Silverado 3500 HD, 2001-2006 Sierra 1500 HD, 1999-2004 Sieraa 2500 4WD, 2001-2010 Sieraa 2500 HD, 2001-2006 Sierra 3500, 2007-2010 Sierra 3500 HD NOTE: Excludes Electronic Suspension and Quadrasteer