Hi,
I don't know, but it seems like a mug warmer could be very useful for those builds where you may have dozens, if not hundreds, little decals to apply, like the stenciling on some modern airplane kits, or containers on a containership. I believe someone in one of the group builds recently indicated that getting all the little stencil decals on their Fighter Jet model took several long nites to do. As such, a mug warmer would seem to maybe helpful in keeping your water warm and preventing you from having to refill with warm water from the tap several times during the process each nite. Plus, when not in use for model building you can still use it to keep your coffee/tea/hot chocolate warm too