Park tool compact bottom bracket tool bbt 18the bbt 32 is a heavy duty investment cast tool for installing and removing the followingeight notch bottom bracket cupsfeaturesshimano isis drive isis overdrivenote the bbt 32 is an updated version of the current bbt 8 the outside diameter of the tool has been changed so it provides a universal fit on all shimano and isis drive eight notch cups the bbt 32 has 8 notches with an outside diameter of nominally 43 4mm the inside to inside width is