Duo Series, 24.1kW, Wood Sauna Stove Have the best of both worlds with the innovative Harvia 20 Duo (WK200SLUX). A unique solution to heating two rooms with one stove. Enjoy the sauna room with great steam and then move to the next room to relax in the glow of a warm fireplace. Required sauna stones 88 lbs (2 boxes) sold separately.