Anyone ever dealt with the 858D hot air stations? I bought a cheap one from amazon and there is a feature in which you press and hold up or down while powering it and it goes into a setting that I don't know what it is. Instead of changing the temp you now are changing a value which can be negative or positive. Mine was default at -2.0. I can't find anything on this anywhere. It states on the product page how to calibrate it but that doesn't work on the one I have. Oh and if you have prime this station is $45.