The GSN50T1-3-6-NAT provides a nominal 50-gallon capacity (47 gallons DOE rated) with a 40,000 BTU input, delivering an 86-gallon first-hour rating at a 90°F temperature rise, making it a strong choice for medium to larger households with higher hot water demand. It uses a standard 3-inch vent and achieves up to 0.65 Uniform Energy Factor (UEF), offering efficient performance and fuel savings.