B-R337A-ENC 333,000 BTUs Low NOx Pool and Spa Digital Heater - Natural Gas - Curpo-Nickel - Salt Water - ASME Certified Serial Number it features a 3-1/2 inch

it features a 3-1/2 inch LCD display

Breather Tube Assembly

Measurements: 1/4 Inch ID x 3/8 Inch OD

4 1/4" Lock Nuts

B-R337A-ENC 333,000 BTUs Low NOx Pool and Spa Digital Heater - Natural Gas - Curpo-Nickel - Salt Water - ASME Certified Serial Number it features a 3-1/2 inchThis Raypak B R337A ENC Digital Low NOx Pool and Spa Heater is 333,000 BTUs, is fueled by natural gas, and features bronze headers, Cupro Nickel fin tube heat exchangers, and is ASME certified. Outdoor hoods come standard with these units. These ASME heaters are salt water friendly and are for residential or commercial installations up to 5,000 feet. Raypak's Low Emissions units are Low NOx certified. The air fuel mixture is maintained by a gas valve