The connectors are gold-plated and the two-core cable is a little rigid. But this seems to be a high cable cross-section and thus owed quality copper cables. The socket connection would be allowed to fail a little shorter. I use the cable for mountain bike tours and can perceive absolutely no cracking or noise. Also, I can generally find no sound loss (use Beyerdynamic dx160ie).
Conclusion: cheap but high-quality cable extension