ProAdvantage™ tankless electric water heaters are designed for commercial applications with a hot water demand under 4.0 gallons per minute (GPM). ProAdvantage models are available in a single heating module design with a maximum flow rate of 2.5 GPM, a dual module design with a maximum flow rate of 3.0 GPM and a triple module design with a maximum flow rate of 4.0 GPM. Mount the unit close to the hot water fixture for best performance.