Skunk2 Racing Ultra rods are manufactured from forged 4340 Chromoly steel then heat treated for ultimate strength. Skunk2 Racing Ultra rods are an x-beam style which greatly reduces weight while maintaining strength by removing material and strategically shaping the beam. This results in a very high strength to weight ratio and is great for circuit and drag racing. The ribs / straps on the pin end increase strength and stiffness under high loads and engine speeds. The step on the big end (crank journal side) is for strength and rigidity to maintain roundness.