I've used a couple times too. the first batch I got had two white wires in it and had to ring out and mark which was which.
I guess it suppose to have black/white, red/white with red trace in order to pair them.
200.6(E) is a good point but it does have continuous white with a red trace, but I am sure someone will misconstrue somewhere down the line. But for right now it is nice to be able to get a 4 conductor RX.
Wm.colt
