AH204423 Bar Assembly ConcaveOne New Aftermarket Replacement Concave Bar Assembly (Insert) Fits John Deere Combines This concave bar assembly insert fits into the threshing area of Fits John Deere STS and S Series combines. Concave inserts provide additional threshing action within the round bar concave section, improving harvesting performance for small grains and other crops. Note: Insert only latch kit and hardware are not included. Order hardware separately if required for