Wheels Manufacturing T47 Inboard Bottom Bracket - For 30mm Spindle, ABEC-3 Bearings, Fits Frames with 68mm-132mm BBT47 Inboard threaded bottom brackets are made from machined aluminum, and thread together directly into T47 frames. Cups have internal bearings for use in BB shell widths from 68mm to 132mm. For use 30mm crank spindles in frames with T47 interface Fits 68mm 132mm shell widths Enduro ABEC 3 sealed bearings are replaceable Grade 10 chromium steel balls, 52100 High Carbon Chromium Alloy Races provide smooth crank rotation Machined aluminum cups with