This component is a half-pulley for the variable-speed drive (variator) on the header of a grain harvester. It forms one side of the split pulley that changes the drive ratio to the header auger and reel, allowing the operator to match header speed to crop conditions. The two halves move axially on the variator shaft, and this half carries the belt contact face that transmits torque from the drive belt. Wear on the belt contact face or the sliding bore causes speed fluctuations and belt slip, reducing harvesting efficiency. This replacement half is machined to the original profile so the belt runs at the correct depth and tension without requiring shimming. On installation, clean the shaft and the sliding surfaces, and verify that the belt aligns with the fixed half before tightening the retaining hardware.