Back in January I purchased this stack from HGLRC in China. Before it was installed it failed in testing. I returned the stack to Cyclone FPV and Taarek correctly the problem and shipped the stack back to me. The service was very prompt. However I was in the midst of an address change and the repaired item just arrived at my new address yesterday. So I haven't been able to try it out yet. It is really great to have a repair facility stateside and have my problem addressed with no hassle.