Wolf Tooth Premium headsets are machined out of aircraft grade aluminum and feature high-end bearings made by Enduro. They are engineered to use the largest possible ball size and are filled with high-pressure waterproof lubricant. A pair of dual-lip seals ride in micro-grooves to keep out water and debris.Stainless steel bearings provide unparalleled corrosion resistanceHighly recommended if your headset will be exposed to wet conditions or sweatUltralight stem cap with integrated spacer, plus an aluminum bolt and a star nut5mm top cover = 16mm total stackO-ring seal prevents water intrusion around the steerer tubeCustom-molded upper lip seal provides additional protection for upper bearingLifetime warrantyItem SpecificationsBearing TypeBlack Oxide SteelColorUltraviolet PurpleDefined Color ListPurpleS.H.I.S UpperEC34S.H.I.S. Stem Clamp Diameter28.6Upper Stack Height16Weight64 Wolf Tooth Premium EC Upper Headset Headset Upper UPC: 810159401104