These saunas are constructed with the environment in mind which accounts for the efforts in using reforested Canadian hemlock wood. The walls are double-paneled and constructed with the thickest interior and exterior wood planks compared to others in the same industry. This all translates to a quality sauna that retains heat more efficiently, heats up faster, and wastes less energy. The far infrared carbon energy-efficient heating panels are 30% larger than saunas heated by ceramic tubes and penetrate skin 40% more to maximize therapeutic benefits. Unlike ceramic heaters, you will never have to replace carbon energy-efficient heating panels. The carbon energy-efficient panels also heat up 30% faster than saunas equipped with ceramic panels and 100% faster than rock and water steam saunas. The 4-person sauna is designed for ease of use and is an outstanding value. Enjoy the convenience of operating your sauna with the interior soft-touch control panel and led display featuring sauna temperature and time functions. This sauna is equipped with a reduced wattage floor and lower bench heater to allow the same benefits and treatment to your legs and feet without the burning sensation of other sauna manufacturers. Enjoy your sauna session with your favorite music through the sauna's built-in FM radio and mp3 auxiliary connection with speakers. This sauna enhances your sauna experience with the bonus feature of the chromotherapy (color therapy) lighting system. This sauna plugs into a dedicated 20 amp 110-volt outlet (please consult a certified electrician for replacing a 15 amp dedicated receptacle to an approved 20 amp dedicated receptacle and 20 amp breaker).