Product information updated on 2021-08-25, Manufactured by MaxTrac Suspension - Part Number MXT:201940, 2019-21 Silverado/Sierra 1500 3 to 4 Inch Rear Lowering Box Kit, REAR FLIP KIT W/ HANGERS, SHACKLES, (2) MAXTRAC SHOCKS, MaxTrac Suspension was founded in 2010 by a group of truck enthusiasts who share the same passion for building quality suspension products while keeping them affordable. Together, with decades of experience and knowledge that the group has built, we will continue to build our name into a brand that is recognized as one of the best in the industry. We take tremendous pride and dedication in providing the highest quality products while passing on the savings to you, Our Customer. The main aspect that sets us apart from other suspension manufacturers is that we provide three types of suspension product lines; Lifting, Leveling and Lowering. The cornerstone of our suspension systems is our spindles, which are made from either ductile-iron or forged aluminum and provide a precise amount of lift or lowering, without compromising ride quality or suspension travel. With our ultra-durable, bullet-proof products, ride height options and affordability, MaxTrac is a brand that you can trust!