Super-smooth steering, quality materials, cutting-edge design and serious durability are all hallmarks of Cane Creek headsets. The 40 Series has light, tough, and beautiful machined 6061 T6-aluminum cups that are internally relieved for even more gram shaving. You also get Cane Creek's corrosion-resistant black-oxide sealed bearings and quality seals throughout to keep the grease in and the dirt out, including Cane Creek's Clip Seal that completely seals the top assembly.