This gear transmits drive from the metering roller to the gathering-chain sprocket on the corn header. It has 12 teeth and is machined to match the original tooth profile and pitch, ensuring correct chain timing and engagement. A worn or missing gear causes chain slip, leading to uneven crop intake and potential plugging of the header. As an original-manufacturer component, the gear is cut to the same hardness and surface finish as the assembly it replaces, so no adjustment of the chain tensioner is needed on installation.