Natural gas water heater, 2" insulation. For installations from sea level to 10,100'. Draft diverter outlet size: 3" with integrated adapter for 4" vent option. T & P relief valve, glass lined tank, anode rod, PEX polymer lined heat trap nipples. PEX dip tube, Next Generation FVIR Approved, stainless steel flame arrestor. Air intake entire base of heater, door mounted manual reset temperature cut off, self powered Honeywell Millivolt Generator Gas Control Valve. 6 year tank & parts warranty. Not for use in mobile/manufactured homes. Meets new NAECA 2015 Efficiency Standards. No. 6 30 NOCS: Capacity: 30 gal, Type: Residential, Style: Short, Fuel Type: Natural Gas, Warranty: 6 yr, BTU Rating: 35,500 BTU, Recovery Rate: 36 gph, Family Size: 3, Voltage: N/A, Wattage: N/A, Energy Factor: 0.63, Vent Size: 3 in or 4 in, Height: 50 in, Width: 20 in, Depth: 20 in, For Mobile Home Use: No, Pkg Qty: 1, Package Type: Box No. 6 30 NOCT: Capacity: 30 gal, Type: Residential, Style: Tall, Fuel Type: Natural Gas, Warranty: 6 yr, BTU Rating: 35,500 BTU, Recovery Rate: 36 gph, Family Size: 3, Voltage: N/A, Wattage: N/A, Energy Factor: 0.63, Vent Size: 3 in or 4 in, Height: 61-3/4 in, Width: 18 in, Depth: 18 in, For Mobile Home Use: No, Pkg Qty: 1, Package Type: Box No. 6 40 NBCS: Capacity: 40 gal, Type: Residential, Style: Short, Fuel Type: Natural Gas, Warranty: 6 yr, BTU Rating: 40,000 BTU, Recovery Rate: 41 gph, Family Size: 4, Voltage: N/A, Wattage: N/A, Energy Factor: 0.62, Vent Size: 3 in or 4 in, Height: 51-1/2 in, Width: 22 in, Depth: 22 in, For Mobile Home Use: No, Pkg Qty: 1, Package Type: Box No. 6 40 NOCT: Capacity: 40 gal, Type: Residential, Style: Tall, Fuel Type: Natural Gas, Warranty: 6 yr, BTU Rating: 35,500 BTU, Recovery Rate: 36 gph, Family Size: 4, Voltage: N/A, Wattage: N/A, Energy Factor: 0.62, Vent Size: 3 in or 4 in, Height: 62 in, Width: 20 in, Depth: 20 in, For Mobile Home Use: No, Pkg Qty: 1, Package Type: Box