With more power than any tankless water heater in its class, the 751 series is ideal for mid-size homes with up to 3+ showers.  These units offer several innovations, such as the dual flame burner, Quick-Connect and Turbo-Flow feature which can boost its output up to 9.8 gallons per minute.  In addition, the piping is 25% thicker than our competitor's to accommodate the higher flow rate demand.  The N-0751M is for indoor/outdoor use.  The N-0751M-DV is for indoor use only.  The N-0751M-OD is for outdoor use only and requires no additional venting parts.