This is a A-418648A1HB Concave, Middle / Rear PN: 418648A1HBMain Description As Following : A-418648A1HB Concave, Middle / Rear P.N: 418648A1HB Helical Bar Concave Features Angled Cross Bars For More Aggressive ThreshingType: Narrow Space, Helical Bar Replaces: CIHCH1680MR IH COMBINE , 418648A1-HB IH COMBINE , Crossed From: AV100244 VAPORMATIC , SW07832 , , SW07862 , , 300-C418648H , , 300C418648H , Found in Section & Models : Threshing Area > Concaves, Case-IH COMBINE: 1680, Case-IH COMBINE: 1682, Case-IH COMBINE: 1688, Case-IH COMBINE: 2188, Case-IH COMBINE: 2388, Case-IH COMBINE: 2577, Case-IH COMBINE: 2588 Associated Items : New Also A-IH-S-1660COMB, A-IH-S-1660COMB And : Helical Bar Concave Features Angled Cross Bars For More Aggressive Threshing Type: Narrow Space, Helical Bar