Hayward IDXL2TRF1930 120/240-volt to 24-volt in AC Transformer Replacement for Select Hayward Heaters Transformer replacement Fits hayward universal h-series low nox induced draft heater models h150fdn, h150fdp, h200fdn, h200fdp, h250fdn, h250fdp, h300fdn, h300fdp, h350fdn, h350fdp, h400fdn, h400fdp Also fits hayward universal h-series and low nox induced draft heater models h200fdp, h300fdn, h400fdp Also compatible with hayward pool and spa hot tub and Universal h-series gas heater models H250IDL2, H350IDL2, H400IDL2, C_PAHEAT New part incorporated on all idl heaters built after 9/20/04; 120/240-volt-24-volt ac