Product Description TK-1S-N Takagi Flash Tankless Water Heater - NATURAL GAS At just two-and-a half feet high, Flash TK-1S generates hot water as needed using just 2.2 cubic feet of space. Weighing in at only 45 pounds and with a first-hour flow rate of over 240 gallons, this compact model produces endless hot water long after conventional units have run cold. Wall-mounted inside or outside, the TK-1S provides 190,000 BTUs of continuous heat, while offering thermal efficiency of 85% using natural gas and 87% with propane. This model uses Natural Gas. It is also available in LPG (Liquid Propane Gas), lead time may vary. Accessories included: Takagi TKBK01 - Wall-mounting bracket Watts 3L150 - Pressure Relief Valve Takagi TK-1S Technical Specificatons