I am interested on 2 persons Ultra-Low-EMF carbon Fiber Sauna. What difference between Model (A) and (C)? Why the Model (C) heavier? Thank you in advance.

The difference in the A, B and C Ultra-Low EMF Infrared Sauna models is simply the cabinet styling. The heater configurations are identical. The C model had more external wood (the horizontal bars) which give a nice modern look and add to the weight.