This chain drives the reel on a grain harvester header. It transmits rotation from the header gearbox to the reel shaft, controlling the speed at which the crop is fed into the cutterbar. A worn or stretched chain causes the reel to slip or run at an inconsistent speed, leading to uneven crop feeding and increased header losses. The chain matches the original pitch and link geometry, so it seats correctly on the sprockets without requiring shimming or adjustment of the tensioner beyond the normal range. On installation, verify the chain tension is set to the specification for the host header.