This HUUM Cliff Mini sauna heater package comes complete with the traditionally designed CLIFF Mini 4kW sauna heater, UKU control (WiFi optional), and sauna stones - everything you need to build your dream sauna experience. The package has been combined for use in sauna rooms from 106 to 177 cubic feet (CF). of 1" to 2" (3-5 cm)Round Sauna Stones