Harvia Virta is a strong, practical and simplistically stylish electric sauna heater for those who want a traditional sauna experience. Virta is a perfect choice for medium to large saunas and excellently suited for those who enjoy frequent and long sauna baths. Sidewall or corner, floor mount install For sauna rooms from 177 to 635 cu. ft. Requires a minimum of 150lbs of stones (4 boxes - AC3020) 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).