This is a A-353727R92 Fan, 4 Blade PN: 353727R92Main Description As Following : A-353727R92 Fan, 4 Blade P.N: 353727R92 New 4 blade fan has a 18.12" diameter, 2.550" pilot hole, and a 3.312" bolt hole center.Dim A (1): 18.12" O.D.Dim B (2): 2.550" Pilot HoleDim C (3): 3.312" Bolt Hole Center Found in Section & Models : Cooling Systems > Fan Blades, Case-IH TRACTOR: M, Case-IH TRACTOR: MD, Case-IH TRACTOR: SUPER M, Case-IH TRACTOR: SUPER MTA, Case-IH TRACTOR: 400 FARMALL (Gas), Case-IH TRACTOR: 450 (Gas) Associated Items : New Also This is An Aftermarket Product And : New 4 blade fan has a 18.12" diameter, 2.550" pilot hole, and a 3.312" bolt hole center. Center Hole: 3.312" Diameter: 18.12" Pilot Hole: 2.550"