This tool engages and fits the 16 teeth of the external bottom bracket cups. The smaller plastic tool fits on the 8 internal splines of the crank bolt and on the 16 teeth of the external crank bolt and on the 16 teeth of the external bearing shells for Shimano BB 9000, for easy assembly or disassembly.Shimano is a registered trademark of Shimano Inc.Plastic tool for 8-fold toothing of the crank bolt and Shimano BB 9000For external bottom bracket cups with 16 teethTool material: CrMo steel / Engineering grade polymerSize: ø5.2 x 4 cm / ø2” x 1.6” (2 pcs)Weight: 137 g / 4.82 oz (2 pcs)