The Rheem RTG20151GD Concentric Straight Vent measures 35.66 inches and features a 3 in./5 in. diameter, designed for optimal venting of gas appliances. This venting solution is constructed from durable materials to ensure longevity and compliance with industry standards. It is suitable for use with Rheem tankless water heaters, providing efficient exhaust and intake air flow. The concentric design simplifies installation and minimizes space requirements, making it ideal for residential applications. Ensure proper venting for your gas appliances with this reliable and efficient venting system.