Notched 20" x 6 mm, concave disc to fit the 5 bolt Joker pattern. Made in Spain out of the same Boron Steel that Horsch Anderson uses.Fits Horsh Joker RT230, RT270, RT300, RT330, RT370; RT Next-Gen 18, 22, 25, 28, 32, 35, 40.Mounting bolt is CFC part number BH1220M