FSA (Full Speed Ahead) MegaExo 19 bottom brackets are for use with 19mm diameter spindles. - For Alloy Cranks with MegaExo 19 BB-AL86/19/SLE - Spindle Interface Type: FSA MegaExo 19 - BB Shell Width: 86mm - Bottom Bracket Shell I.D.: 41 - BB/Frame Interface: BB86