The Ultra Low NOx Burner Kit for U1XR403S-337 by Bradford White is engineered for optimal performance in water heating applications. This kit operates on liquid propane (LP) and is designed to meet stringent low NOx emissions standards, ensuring compliance with environmental regulations. Made from high-quality materials, it offers durability and reliability. The precise dimensions and specifications make installation straightforward, allowing for seamless integration with existing systems. Ideal for service and replacement, this burner kit enhances the efficiency of your water heating system while minimizing environmental impact.