BikeHard Carbon 1 1/8" Headset Spacer UD 5mmThe BikeHard Carbon 1 1/8" Headset Spacer is uniquely distinguished from other spacers on the market as a result of a patented technology which reduces overall material on its interior. Regular carbon spacers are completely circular on both their interior and their exterior. The BikeHard spacer is internally weight relieved to drop approximately 30% weight relative to this normal carbon spacer. As a result of both the weight reducing splines and the high grade to the carbon material used, these spacers are some of the lightest spacers in production in the world today.850228007936