Yeah Racing TRX-4 brass spring retainers
Made for Traxxas’ TRX-4 trail truck are brass spring retainers from Yeah Racing. Machined from high-quality material and sporting a shiny, natural finish the cups add weight to the lower part of the chassis for an overall lower centre of gravity and added traction. The set includes four spring retainers that are a direct replacement for the stock parts.
Source: Yeah Racing [yeahracing.com]