Smaller coaches can be upgraded with the ES, because this pump has been specifically designed for after market installations. Powerful Flows — The ES delivers a 3.5 gpm flow rate, higher than nearly anything else for the RV industry. Reduced power consumption helps ensure compatibility with existing electrical systems. Silent Operation — The ES version is even quieter than the Aquajet RV version. The patented, variable speed controller and "soft-start" features eliminate most cycling related noises. Easy Installation — Lower amperage draws eliminate the need to use electrical relays, etc., regardless of current electrical configurations. Installation is simplified to the point of true "plug-and-play performance.” 55 Aquajet AES, 6.5 Amp Water Pump.