Park Tool BBT-9 External Cup BB and Hollowtech II Tool Tool

The BBT-9 is used to remove and install external bearing crankset bottom brackets.One end of the BBT-9 securely engages the 16 notches of the bottom bracket cups.The other end of the tool engages the 8 internal splines of the crank arm adjustment cap.The BBT-9 fits cups and lockrings with 16 external notches and an outside diameter of approximately 44mm.'