This upper sieve is part of the combine harvester cleaning assembly. It sits in the cleaning shoe, where it receives the threshed material from the grain pan and separates lighter chaff from heavier grain and MOG. The angled louvres direct airflow upward through the mat of material, allowing the fan to stratify the crop stream before it reaches the lower sieve. A worn or damaged sieve allows grain to pass into the tailings return or be lost out the back of the machine. This component is manufactured to match the original sieve's louvre geometry and frame dimensions, ensuring it seats correctly in the cleaning shoe housing without altering the air distribution pattern.