#CUP-2 - Caster Racing EX-1 and EX-1.5R - 2.5mm "Flexy" Carbon Fibre Upper Deck Support System. Gets rid of most chassis bending, Keeps the buggy's handling very consistant. Highly recommended. (Designed to fit a brand new chassis, some tweaking may be needed for old used chassis') Easy to install. This version allows more twist and flex compared to the 3mm stiffer version but still keeps the chassis straight. Good for bumpy, loamy and rutted tracks.