The GeneralAire 6009 is the correct left-hand lid assembly for the following humidifier models:
The GeneralAire 975-13 Left-Hand Lid Assembly is a replacement lid assembly for the GeneralAire 709, 1042, and 1099 Legacy Series Humidifiers. The 975-13 L.H. lid assembly is a crucial internal component of your Legacy humidifier unit and helps ensure the proper flow of moisture into your home. The 6009 assembly is a genuine GeneralAire replacement part.
GeneralAire 975-13 Left-Hand Lid Assembly specifications: