TRX-4 Technology and Innovation-Now Available as an unassembled kit! The Traxxas TRX-4 Scale and Trail Crawler set the standard for off-road versatility with its radical design and rugged durability. The new TRX-4 chassis kit combines the same innovative features as the RTR vehicle with the fun and excitement of building your own kit. Build your own portal axles, high/low range transmission, and remotely locking differentials. All the parts are organized neatly in labeled bags with waterproof electronics and pre-assembled shocks and suspension links. A fully illustrated color manual makes the kit as much fun to construct as it is to take off-road.