Air Mixing Technology- Saunum's patented air blending system mixes cold, oxygen-rich air from the floor with hot, oxygen-poor air from the ceiling. This solves the discomfort often associated with saunas, delivering full-body heat and oxygen-whether you prefer extreme heat or gentle warmth. European Design- Features an elegant stainless steel finish and combines Scandinavian design with high-quality materials. Massive Stone Capacity- With a large 132-pound stone capacity (requires 4 boxes, sold separately), this heater provides softer, more even heat and luxurious steam-key elements of a true Nordic sauna experience. Himalayan Salt Reservoir- Salt spheres placed in the air stream release beneficial salt ions throughout the sauna, promoting wellness. Suitable for sauna rooms from106 to 212 cu. ft. UL-listedfor safety compliance.