(1) Most pre-fab kits require vinyl or concrete (waterproof) flooring. Because this is portable, assume waterproof layer under wood layer of flooring? Please describe. (2) What is the brand of heater included? Is it a Tylo?

That sauna comes in two halves. It is made using insulated panels, similar to our pre-built saunas. The floor panel is framed and insulated with tongue and groove cedar inside. We also provide a cedar duckboard floor grid for the walking space. So a waterproof barrier is not required. If you have water on the floor of a sauna, you are putting too much water on the rocks. Just enough to steam off, not enough to pour through the rocks. The heater is a Baltic 1.7kw (110v) traditional sauna heater. It is a heater that we built private label for the factory.