The ICON Vehicle Dynamics 2021-2023 Bronco Coil Seat Kit is used when upgrading an existing pair of ICON 2.5 Series Bronco rear coilovers equipped with spring part number 148350 with the ICON Heavy Rate Rear Coil Kit. Over time different revisions of the ICON triple rate rear Bronco coil have required coil sets of varying heights to achieve proper ride height. This precision CNC machined, anodized aluminum coil cup kit is the correct height to be used with the ICON Heavy Rate Rear Coils to achieve the ICON recommended rear ride height.