Off the top of my head, I am not sure what brand mine is. I don't think it's anything fancy though. Works great and I use it all the time, almost everytime I wear a pair of boots now. I have a pair of Danners and I don't think it ruins the leather at all, my uneducated opinion is that it probably helps the boot? My most worn boots are 2 different pairs of Mucks, and I have not noticed years worth of the boot dryer damaging them at all. I wear Muck chores a lot in the summer doing yard work and in the fall hunting, and put them on the boot dryer almost each night. Wear Muck Arctic Pros in the winter ice fishing and what not, and have also not noticed any damage.
I've never left a pair of boots on for days. Usually just plug them in at night and unplug them the next morning, and they are always dry and warm.