Hello , Mr. cheater bar and Mr. hammer will create Mr. dented fixed cup if you don't have a way to hold the fixed cup tool in place, espesially if the installer used some locktite. the Campy tool grabs the cup from inside(throught the axle hole and holds the wrench in place. A bolt and carefully selected washer(s) will do the trick in a pinch.
David Cowie No more ruined alloy cup's Sutherlin, Or
p.s. thanks for the responce for my GB stems, still have a few left..