The GeneralAire 7104 is the correct replacement drum assembly for the following humidifier models:
The GeneralAire 81-22 Humidifier Drum Assembly is a replacement drum assembly for the GeneralAire Legacy Drum Model 81 Humidifier. This drum assembly includes the following parts: 81-8 drum end- closed; 81-15 replacement evaporator sleeve; 81-9 drum end - open; 81-10 drum shaft; and P188 retainer clip. The GeneralAire 7104 allows your drum-type humidifier to operate at full functionality and to deliver clean humidification throughout your home.
GeneralAire 81-22 Humidifier Drum Assembly specifications: