Heat-treated steel wrench specifically for the removal and installation of bottom brackets. Powder-coated for corrosion resistance. Fits externally ringed bottom brackets with 16 splines, such as Shimano Hollowtech II. Includes preload tensioning tool. Heat-treated steel wrench specifically for the removal and installation of bottom brackets. Powder-coated for corrosion resistance. Fits externally ringed bottom brackets with 16 splines, such as Shimano Hollowtech II. Includes preload tensioning tool.