The Rheem Refractory Uncommon (Front & Rear) 399 is designed for optimal performance in heating applications. This refractory component is essential for maintaining heat efficiency and safety in your heating system. Made from high-quality materials, it ensures durability and longevity. The dimensions are tailored to fit specific Rheem models, providing a seamless installation experience. This part is crucial for compliance with safety standards, ensuring your system operates within the required parameters. Ideal for use in residential and commercial heating systems, it supports various applications, enhancing overall system reliability.