Economical: Some consumers have reduced hot water heating costs by up to 50%;No costly storage of hot water when it is not needed;Heat up to 240 gallons per hour;Consistent water temperature;Stainless steel heat exchanger;88% efficient;Proven trouble-free performance;Safe: ETL and CETL home and mobile home approved;Direct vent or chimney vent;Small, compact size;Limited 10 year warranty