Adding 20 percent more Btu than its GU100 Model, the Eternal GU120 Model provides homeowners with hot water for up to two applications simultaneously. It can be used in retrofit and new construction projects. Features include ½-inch gas line connection, 3-inch PVC venting material, top-mounted water taps, and 100 percent stainless steel heat exchanger with a 2-gallon reserve tank inside. The digital display shows temperature adjustment and self-reporting diagnostics. The patented self-cleaning counter flow design helps to flush sediments out. The unit is compatible with low-flow WaterSense fixtures and most recirculation systems.