I replaced my RM650 (I bought it a long time ago, at the dawn of this series, I can't remember exactly when, perhaps 5 years old), and I handed it to my sister since her Chinese without certifications, etc. I can't remember precisely when I got it, but it was at the beginning of this series. worked for 9 years and died, I took 850x for myself, the wires are really harder (manufacturer maybe different - I don't know for sure), I took it with a margin because there is a wish to replace the glands See full review