Features- Condensing natural gas tankless water heater- Indoor installations only- 1 major appliance or shower at a time- No standing pilot- 12 gallon minimum water flow ignites burner- Maximum 160000 btu input- Delivers 6-6 gallons per minute at 45 degree fahrenheit rise- Vertical or horizontal venting allowed- Vents with 3 in- Or 4 in- Schedule 40 abs, PVC, cPVC or polypropylene pipe fittings- All venting material purchased separately- Built-in freeze protection- 120vac 60hz electrical- Digital display- ...