I used this kit to accommodate for the inner ring of a 53/39t bottoming out on the chainstay - the frame builder hadn't dimpled the tube to account for this, so only a compact would clear. This shim kit allowed me to push the DS cup out by 0.5mm, allowing the standard Campy UT crank to clear. Perfect. Customer support was excellent: I asked about my particular problem and got a personal call to discuss it.