The Park Tool BBT-9 Bottom Bracket Tool is a precision tool designed for installing and removing Shimano Hollowtech II bottom brackets and similar 16-notch external bearing cups. It features a laser-cut, heat-treated steel construction for durability and a secure fit. The tool also includes a 8mm hex fitting for adjusting and removing crank arm preload caps. Ideal for home mechanics and professional workshops, the BBT-9 ensures smooth and efficient bottom bracket maintenance