The Navien NPN-180U Tankless Gas Water Heater is a versatile and efficient heating solution for both indoor and outdoor use. With its stainless steel tank lining and instantaneous heating system, it provides hot water on demand without the need for a storage tank. NThe built-in control and Wi-Fi capability allow for easy monitoring and adjustment, while the cascading feature enables multiple units to work together for increased hot water supply. Color options in brown or blue make it suitable for various decor settings. Additionally, the low NOx emissions make it an environmentally friendly choice for heating needs.new in box. Must be installed by lisenced contractor to register for warranty coverage.