Our Hot Bodies D8T Carbon Arm Inserts were developed and used by Ty Tessmann to win the 2014 Dirt Nitro Challenge which offer your Truggy another great tuning feature by reducing the flex and twist in the arm. The carbon inserts starts as a 3.9mm thick piece which is milled down to 2mm thick while leave 6 islands still at 3.9mm and to finish them up the islands are pocketed in the middle to 2mm to remove unnecessary weight. These inserts are installed on the bottom of the arm and the islands key around the molded ribs in the arm. Installing these pieces will take some personal time but as Ty will tell you, the rewards are worth it. Ty has put together an installation video to show you his process for installing. With every set* we are including the screws and the two drill bits needed to install them (2.52mm and 3.04mm).