To fully take advantage of ICONs current 2017-UP F150 Raptor offerings, ICON engineers decided to scrap the OE leaf springs and develop a replacement that addressed a couple issues found in the R&D process. The result is a user-adjustable multi-rate leaf pack that offers a major performance gain for almost every Raptor setup imaginable. To increase the ride quality of the truck and gain additional droop travel, the spring rate was designed to be slightly lighter than factory, which was found to be on the stiff side for smaller, choppier terrain. While most Raptor owners will embrace the improved ride quality this provides, there are those who have outfitted their trucks with a significant amount of weight and require more load carrying capability. Understanding this, ICON engineers designed the leaf pack with an additional leaf (included with kit) that can be exchanged or added to the pack, yielding an additional 20% or 40% spring rate that will work well for heavier vehicles.