3/4 inch NPT water connections on bottom of the unit for easy installation Saves space with a compact design Thermostatic control for precise outlet temperature Saves energy! this unit is 99% energy efficient Bottom water connections 99% Energy Efficient Ease of installation - No T&P valve needed; 3/4" Male NPT connections on bottom On demand hot water - never run out Temperature rise at 1.5 GPM = 87°F 0.7 GPM Turn on; 2 GPM flow rate