The Cognito 210-90211 CMS Fox Front Leveling Shock for your 2011-2019 GM 2500HD/3500HD provides you with race-dominating technology and performance in a hassle-free bolt-on package. Their heat-reducing design includes a metal-impacted aluminum shock body that dissipates heat faster than conventional steel. Inside the Internal Floating Piston (IFP) separates shock oil from a high-pressure nitrogen gas chamber that provides a predicable ride quality capable of handling the roughest road conditions. Combine these new technologies with a competitive price for a winning combination. Sold individual must order quantity of 2, for use with Cognito Upper Control Arm Kit only. Features: Made In The USA! Black Anodized 6061-T6 Billet Aluminum Race-Developed High-Flow Piston Design Aluminum Shock Body Dissipates Heat Three Times Faster Than Steel Specially Formulated For Ultimate Performance At Variable Temperatures Notes:Â When using with Cognito Upper Control Arms you must also purchase shock extender kit SEK-2011-8-1. Sold individual must order quantity of 2, for use with Cognito Upper Control Arm Kit only.