This drive chain transmits rotational force from the gearbox output to the reel shaft on the header of a grain combine. It engages the sprockets that rotate the reel, which guides crop material into the cutterbar and auger. The chain includes a connecting link for installation. A worn or stretched chain causes the reel to slip or run unevenly, leading to inconsistent crop feeding and potential slugging at the auger. The manufacturer machines the pins and rollers to match the original sprocket pitch, so the chain seats correctly on the drive sprockets without requiring shimming. On installation, verify the chain tension and align the sprockets to prevent side-loading.