Chris King bottom bracket Fit Kits are used with Chris King bottom brackets to ensure that cranks mate perfectly with bearings, extend product life, and reduce the potential for noise. Fit Kits will also allow you to use one bottom bracket with a wide array of cranks, if you happen to change you cranks in the future.Fit Kit 1 DUB A covers all DUB mountain fitments, as well as DUB road fitments with ThreadFit T47 bottom bracketsFor DUB mountain cranks with a 68mm BB shell you will need two 2.5mm cup spacersFor DUB Super Boost + cranks you will need one additional spindle spacer kitFit Kits extend the useful life of both your bottom bracket and your cranks, it reduces the potential for noise, and it also allows you to use one bottom bracket with a wide array of cranks Chris King Bottom Bracket Fit Kits Cup Conversion Kit UPC: 841529096194