820-287C Disc Opener Assembly 15” x 4mm For Great Plains Planters & Grain DrillsOne New Aftermarket 820 287C Disc Opener Assembly 15 x 4mm For Great Plains Planters & Grain Drills Fits Great Plains Models: Planters Late Model Row Units 1999 and Later Grain Drills Late Model Drills 1999 and Later with Heavy Duty HD00, HD10, 15 and 25 Series Openers Replaces Part Number: 820 287C Specifications: 15" x 4mm HD Disc Opener Assembly Has 53mm OD Bearing x 5 8" ID.