COZY has taken the ancient craft of building a sauna to a higher level. The part of a wood-burning heater that must be the strongest, the flame cutter, is made of sturdy, 5mm-thick stainless steel making COZY heaters extremely durable. This unique wood-fired sauna stove is hand-made in Estonia, where sauna bathing is ingrained in the national culture. The Cozy Heat O wood-burning sauna stoves are perfect for mild and long-lasting heat, designed for pouring water over hot stones to create intense and luxurious steam for a more gratifying sauna experience. At the heart of the Cozy Heat O is its innovative circular rim design, which not only enhances the heater's aesthetic appeal, but also ensures efficient heat distribution throughout your sauna space. Installation and operation manual Stove utilizes 25%-40% less fuel than comparable sauna stoves Boasts minimal safety distances Sauna room sizes:12kW- 210 to 423 cu.ft.18kW- 317 to 635 cu.ft. Stone Requirements:12kW- minimum of 265lbs of stones18kW- minimum of 353lbs of stones 12kW- minimum of 265lbs of stones 18kW- minimum of 353lbs of stones Please note that each natural stone is unique in shape and size. We recommend purchasing an additional box of sauna stones to allow you to choose the highest quality of stone for fit, form, and function (Additional freight charges will apply).