These are the new optional high-performance Kevlar-reinforced drive belts for the T4 touring car. The belts are very thin and as flexible as possible for an extremely effective transmission that dramatically reduces friction and increases performance.
#305434 Xray Low-Friction Kevlar® Drive Belt Front – 3x513mm
#305447 Xray Low-Friction Kevlar® Drive Belt Rear – 3x189mm
Source: Xray