Wrong items sent which took a week of technical support emails to sort. In the end I discovered the problem myself: I had been supplied the 'telemetry' version of the KAPPA module instead of the 'modem' version that I ordered (there are no marking to distinguish between versions). Even though I clearly explained exactly what was happening (I even sent oscilloscope traces), they were still unable to diagnose the problem. Having glanced at the 'telemetry' version datasheet I quickly realised that my modules were behaving exactly as those versions. The modules were sent back for a refund as I had since bought the correct modules from a distributor as I was on a tight timescale. Just over 1 month later I received the modules back - presumably re-programming to be a 'modem' version - although there is no explanation as to what they have done to them. So I didn't get a refund, just the 4 modules back which I now have no use for! In the future I think I will buy from a distributor as they seem to handle their stock better than the manufacturer themselves! Overall: disappointed.