Check the listing for details. NUKEPROOF NEUTRON ZS66/46 E-MTB LOWER HEADSET WITH BUMP STOP CROWN RACE. Condition: New. Listed at 29.06 USD. Nukeproof Nuetron press fit lower cup, bumpstop crown race and bearing headset assembly To fit all taper frames that require a lower ZS66/46 press fit cup type headset For all Electric mountain bikes that have a lower frame internal diameter of 66mm and a tapered fork that requires a crown race with an internal diameter of 46mm For Steerer: 1-1/8" - 46mm lower tapered fork Colour: Black Includes every part as pictured (Cup, bearing, bump stop crown race) Specifically developed for electric mountain bikes (E-MTBs), this headset offers maximum durability and longevity in all conditions.The Neutron E-Bike headset is an alloy construction with no plastic parts in vulnerable high-stress areas, using a steel cartridge bearing, offering a robust and reliable package. With an inbuilt bump stop, the headset is designed to protect the cables in the event of a crash by stopping the bars from spinning too far