This Lochinvar flue connection is a crucial component designed for efficient venting of combustion gases in heating systems. With a diameter of 4 inches, it is compatible with the WH399 model of water heaters. The product is made from high-quality, durable materials that can withstand high temperatures and corrosive gases, ensuring long-term reliability and safety. It facilitates the safe expulsion of exhaust gases from the heater to the outside environment, thereby preventing potential hazards associated with gas build-up. The flue connection adheres to industry standards and specifications for optimal performance and safety.