This adapter kit allows you to use your old external bottom bracket mountain cranks (24mm spindles) with your new BB30 or Pressfit 30 frame. Technical DetailsDupont Delrin constructionCompatible with mountain cranks from Shimano Hollowtech II, Race Face X-Type, or FSA MegaExo systemsNot compatible with SRAM/Truvativ GXP cranksetsFor BB30, use included spacer