A absolutely top-of-the-line 1" threaded alloy headset for the most discerning rider. It features oversized sealed cartridge bearings, so packing and re-greasing bearings are a thing of the past. Easily replaced bearings that can be dropped in, not pressed; and a rubber seal on the lock nut.
Stack height is 41mm with a 26.4mm split crown race for easy installation.
Upper - EC30/25.4-24tpi - S.H.I.S.
Lower - EC30/26 - S.H.I.S.