PTO Shaft for Most 4' & 5' Shearpin Rotary Cutters PTO Shaft for Most 4' & 5' Shearpin Rotary Cutters Medium/Heavy Duty Series 4 PTO Shaft 1-3/8" 6 Splined (540) on the Tractor End 1-3/8" Smooth with 1/2" Shearpin Hole on the Cutter End Minimum Working Length is 35.8" Maximum Working Length is 49" Included is 3 Grade 2 Shear Bolts with Nuts