Product Description TK-3-N Takagi Flash Tankless Water Heater - Natural Gas Takagi's smallest, most versatile and most powerful residential model. Connect up to four units to meet the demands of even the largest homes! The compact T-K3 measures under 14 inches wide, so it will fit snuggly between two wall studs to save space. But the T-K3 is also powerful. With Takagi's new easy link technology, the T-K3 will meet the hot-water needs of most high volume residential applications. This model uses Natural Gas. It is also available in LPG (Liquid Propane Gas), lead time may vary.