This is a A-05870021 Blade, Disc Mower, LH PN: 05870021Main Description As Following : A-05870021 Blade, Disc Mower, LH P.N: 5870021 Hole Diameter: .826"/21mmLength: 3.937"/100mmThickness: .157"/4mmType: 10 LHWidth: 1.85"/47mm Replaces: 0587-0021 AGRIQUIP Found in Section & Models : Hay Tool Parts > Disc Mower Blades, Agriquip MOWER, DISC: ALL CM SERIES, Marangon MOWER, DISC: SEVERAL Associated Items : New Also This is An Aftermarket Product And : Hole Diameter: .826" / 21mm Length: 3.937" / 100mm Thickness: .157" / 4mm Type: 10 LH Width: 1.85" / 47mm