This 5″ combustion blower fan blade is a double-sided impeller that is used on most freestanding Harman Pellet Stoves. Check out the compatible stoves tab to verify which impeller you need for your stove.
If any of the petals (fins) are bent, your stove may vibrate. To fix this, you can sometimes bend them back to help balance the motor. It is suggested to replace the impeller if the metal is corroded, if there is metal missing or if the impeller is unbalanced through wear and tear.
If you are replacing your combustion blower motor for any reason, it is suggested to also replace the impeller. Harman has engineered 3 different sizes for their various stoves which is why they are not already attached to the motors.