The HUUM HIVE 12kW sauna heater provides modern elegance for larger saunas like those in health clubs, spas, and gyms. This floor-mounted heater is engineered to hold 528 lbs of stones for unmatched efficiency and performance in sauna rooms up to 883 cubic feet (CF). Required control, extension box, and sauna stones (16 boxes) sold separately. For sauna rooms from 424 to 883 cu. ft.