The MiniMax NT heater features strong corrosion resistant stainless steel burners, durable headers, a composite top, and a weatherproof anodized aluminum exterior. The MiniMax NT heater features energy-saving "Hot Surface" ignition, fast heat-up, and exceptional efficiency for lower costs. Thermal efficiency in excess of 82% for minimum operating cost Precision Digital Electronic Thermostat Fan assisted venting system Ceramic tile insulation prevents heat loss for greater heat transfer efficiency Long-life corrosion resistant composite header system integrated with premium copper high-fin heat exchanger for maximum thermal efficiency LED lights on control panel provide at-a-glance monitoring of major heater functions Patented flow valve with long-life power element minimizes condensation, erosion, and scaling