Intertherm Ventilaire Blade Only. These Heater Accessories by Intertherm are designed for use with the Ventilaire IV system. This Intertherm 667246R Ventilaire Blade Only helps bring in fresh air to the living space and prevents heat from being lost from attics during extreme heat waves. However this attic ventilator should not be used as a method of repairing or replacing your unit. If you suspect there is a problem with your unit you should call the manufacturer or installer for an inspection. For more brand name Heaters visit our section on Air Quality and Ventilation for more useful guides and information. Features of Intertherm 667246R Ventilaire Blade Only When moisture-producing activities (cooking bathing etc.) are occurring operate exhaust fans Avoid hanging clothes to dry within your manufactured home Vent all fuel burning appliances Avoid using humidifiers Replacement blade only Package Contents: Intertherm 667246R Ventilaire Blade Only Intertherm 667246R: Ventilaire Blade Only