Off-road design is heading towards a bike which is year by year lighter, compact and stiff. This caused Arrow to develop a new line of systems to match the needs of off-road riders. Arrow most important features like lightness, performances, reliability are now combined to the experience coming from years and years of races and ?dirt? work on ?dirt bikes? (work leading Arrow to a real dominance in the MX World Championships of the last ten years). This background led to the Off-Road Thunder exhauts. The diamond shape, a major distinguishing feature of Arrow brand, a real ?trade mark?, ensure the best balance between inner volume and external dimensions, matched directly to the rear endcap, designed to fulfill the requirements stated in worldwide racing rules. TIG welding, top level materials (silencer canisters are available in titanium or aluminium) and a focus to details contribute to place Off-Road Thunder exhausts on the top level among ?dirt? systems.