Coulter & Speciality Blades 20FL-COMBO 20” DiameterFlutes To The Edge8 Bolt Holes3-7/16” Center Hole 20FLC-COMBO 20" DiaFlutes With Smooth Edge 8 Bolt Holes3-7/16" Center Hole 20PL-COMBO 20" DiameterSMOOTH (Plain) 8 Bolt Holes3-7/16" Center Hole 17WB-COMBO 17" Diameter12-wave, 3/4" height 8 bolt holes3-7/16" center hole 20NO-COMBO 20" DiaNotched RIM8 bolt holes3-7/16" center hole 20VT-COMBO 20" DiaZ-shaped flutes25 flutes, 1/2" overall 8 bolt holes3-7/16" center hole ShieldAg Blades 17” - 27” Identification Chart