Zipp Vuma Standard Bottom Bracket

This is a Vuma Standard bottom bracket that is designed specifically for use with the Zipp Zuma chainset and can only be fitted with a unique Zipp bearing tool, made by Pedro's, that comes with the crankset.
This uses an ABEC 5 grade race and Grade 10 steel balls that are no less than 2.5 times as round as the rest of the industry.