Thermel heater, 425W, 110V Hot Plate w/ control, 4" Dia. Lab distillation 957A.

This appears to be New Old Stock in original box.  Replacement 4" heater plate with mechanical temp control.  Thia was a spare part for a distillation heater in a lab.  Tgus is untested but appears to be in new condition.   Sold as is, no warranty or returns. 

Box has writing on end: 18-6542-01