Features lightweight precision machined aluminium cups logic smaller upper scale angular cartridge bearing saves weight larger lower bearings boosts strength and durability uses ritchey grease and sealed design for years of trouble free performance anodized black finish fits standard 118 or 1 inch headtubes headset specs for 118 upper shis ec34286 lower shis ec3430 if unsure about shis headset sizing click the link to the website bicycleheadsetscom