The BBT-18 is a heavy duty investment-cast tool for removing and installing components with an eight-notch tool fitting, including select cartridge bottom brackets, as well as chainring lockrings on some e-bike drivetrains. BBT-18 FEATURES Installs and removes the following components with eight-notch tool fittings: ShimanoA(R) OctalinkA(R) drive-side bottom bracket cups with external notches ISIS Drive bottom bracket cups including TruvativA(R) and BontragerA(R) Front chainring lockring for BoschA(R) Gen 3 and Gen 4 e-bike systems Front chainring lockring for SpecializedA(R) Levo Brose e-bike systems Tool specifications: 8 notches with a nominal outside diameter of 43.4 mm The hole in the center of the casting is 22.5 mm, and will not fit over 30 mm spindles Features 36 mm wrench flats