From HB Racing:
These sway-bar sets for the D418 give racers an extended range of stiffness to help tune the car to track conditions. The Front and Rear Sway-Bar Sets have 1.6mm, 1.8mm, and 2.0mm bars, each labeled with a tag that shows the stiffness. These new sway-bar sets are stiffer than the original sets, and are aimed at Astro/Carpet racing and high bite tracks.
#204415 – D418 Front Sway-Bar Set (1.6/1.8/2.0mm)
#204416 – D418 Rear Sway-Bar Set (1.6/1.8/2.0mm)
Original D418 Sway-Bar Sets for reference:
#112798 – D418 Front Sway-Bar Set (1.2*/1.3/1.4mm)
#112799 – D418 Rear Sway-Bar Set (1.2/1.3/1.4*mm)