Campagnolo ultra torque screw tooltool for assembling campagnolo record chorus and centaur ultra torque cranksets made to mate to a crescent wrench a 17mm box end wrench or a 10mm allen wrench to give proper leverage when tightening this critical bolt featurescompatible with chorus and centaur ultra torque cranksetsmates to 17mm box end wrench or 10mm allen wrench buy campagnolo chain tools from chain reaction cycles the worlds largest online bike store