HUUM Digital On/Off, Time, Temperature Control with Wi-Fi, BlackSKU H2004012 UKU Wi Fi sauna controller makes sauna heating very easy and comfortable. With UKU you can heat your sauna on the spot or do it from your phone through HUUM mobile app. (For HUUM sauna heaters over 11kw and up to 18kW, an UKU Ext Box is required.). Sauna heater sold separately Features Sleek Black control display panel For heaters up to 18kW (over 11kW requires extension box) Settable on off, time, temperature, and delay Settable