SKUNK2 RACING K24 ULTRA SERIES CON CONNECTING RODSSkunk2 Racing's Ultra Series X Beam Connecting Rods are manufactured from Forged 4340 Chromoly Steel. All forgings are then fulley machined and subjected to a battery of processes that include heat treating, shot peening, and magnafluxing to insure the ultimate in strength! Finally each set is balanced to within + 1. 5 grams. Our x beam design greatly reduces weight while maintaining strength by removing material and strategically shaping the beam;