Hayward FDXLBWR1930 FD Combustion Blower Replacement for Hayward Universal H-Series Low Nox Pool Heater Fits Hayward Universal H-Series Low NOx pool heater models: h150fdn, h150fdp, h200fdn, h200fdp, h250fdn, h250fdp h300fdn, h300fdp, h350fdn, h350fdp, h400fdn, h400fdp Excellent Salt Water and chemical Corrosion Resistance Exclusive 'Totally Managed' Cupro Nickel Heat Exchanger Water Flow Same Water Velocity Through All Tubes for Faster Heating. Up to 18% Savings by Reducing Pump Run-Time 2" x 2 1/2" CPVC Union Plumbing Connections. Low NOx Emissions - Meets Clean Air Quality Standards