The Damper is an OEM part for Samsung microwaves. It regulates the airflow within the microwave, ensuring that steam and smoke are properly vented out during cooking.  Causes of a bad damper can include wear and tear from regular use, accumulation of grease or debris, and damage from sudden impacts. Symptoms of a bad damper include: Inadequate venting of steam and smoke Unusual noises coming from the vent area Increased condensation inside the microwave This OEM Samsung part is also compatible with some Kenmore models.DE72-40022A (AP4230225) replaces 2083930, PS4234478.