For indoor or outdoor installations on pools and spas. Features include an LED temperature readout with dual thermostat controls, temperature safety lockout, and 6-position control panel. PMG burner technology requires no outdoor draft hood. Proven Dura-Glas rust-proof construction with plastic manifold and PVC union connections. Heavy-duty unit with cupro-nickel exchanger stands up to the harshest of applications, like low pH, high flow or heavy use. An Eco Select Choice: Max-E-Therm high performance heaters offer best-in-class energy efficiency. Plus, they are certified for low NOx emissions, making them eco-friendly favorites.