Intrax obtained the exclusive contract with the Radical Masters and the national cups, partly due to its good service and experience with competition shock absorbers. Radical obviously was aware of the Intrax quality, as 99% of their customers order the Radical with the Intrax shock absorber. But they also saw how fast Intrax is, and by that, we don't only mean on the circuit, something already known for a long time.
Intrax delivers very fast service when there are back to back races (two successive race weekends) and there is damage to the shock absorbers in the first weekend. Quick action is wanted then. You can send the shock absorber to the Intrax factory by courier. As soon as the shock absorbers are received, Intrax will start servicing them and tries to send them back the next working day.
In a Cup where more than 60 similar cars drive in a single weekend, it is often impossible for the Cup manufacturer to bring enough spare parts for everyone. This way, nobody has to miss a race because they have no shock absorbers.