Takagi T-K4-OS-NG (Natural Gas) Outdoor Tankless Water Heater 8.0 GPM from Tankless Collection The T-K4 models have an impressive max GPM of 8.0GPM, enough capacity to meet the needs of most residences. The T-K4-OS has a built-in power venting system and was designed specifically for outdoor installations. The T-K4-OS does not require any additional Category III venting or vent caps, making installation one step easier for installers. Features: Capacity 2-3 Showers (Depending on climate) Gas Fired Tankless Water Heater Outdoor Only Safety Features: Air-Fuel Ratio Sensor (AFR), Exhaust and Water Temperature Safety Control, and Overheat Cutoff Fuse Internal Freeze Protection System Manual reset switch Specifications: Min 11,000 BTU/h Max 190,000 BTU/h Energy Factor - 0.82 Dimensions - H 20.3" x W 13.8" x D 8.5" Weight - 38 lbs Clearance- Top: 36", Bottom: 12", Front: 24", Back: 1", Sides: 2 " Venting: No Venting Required Electric Ignition Accessories: TK-RE02 - Temperature Remote Control (Included) TK-PC01 - Pipe Cover TK-RB02 - Recess Box